CHAPTER FORTY FIVE
piece of my heart.
season four, episode thirteen.

"THERE SHE IS," MARK GRINNED WHEN HE SAW WHO CAME THROUGH THE DOOR TO THE LAB. Addison, who was back in town from Los Angeles for a case, waved at him as she moved to stand over his shoulder.

"Just coming in to check on my patient's skin flap," she said, checking his progress.

"Amazing, right?" he boasted, pointing to what he was working on. "I pulled a couple of stem cells from the baby in utero, six weeks later, I have grown skin. Like god."

"This place is exactly the same," Addison laughed. "You are exactly the same."

At that moment, Cassie walked in with a grin on her face. Things between her and Mark had become a bit less awkward over the past few days, though the tension was thicker than ever.

"Hey Mark, I grabbed you some—" Cassie cut herself off when she saw who was standing in the room. "—coffee."

Addison shuffled her feet. "Hey."

Slowly, Cassie stepped right past her, setting the coffee down on the desk next to Mark. He raised a brow, confused as ever. "Cass, what's going o—"

"Hey?" Cassie whipped around and raised her voice at the redhead, who was startled by her outburst. "You move to LA without so much as a goodbye, and you have the audacity to say hey?"

Addison looked to Mark for help, who was trying to hold back an amused smile. "Sorry?"

"You leave for months, after I finally got over everything that had happened in the past, after you practically begged me to forgive you, without saying goodbye, and you say hey?"

Cassie had her arms crossed over her chest as she stared down the attending.

Addison, who had expected this to happen, took a deep breath, and moved to grab something out of a small cardboard box she'd brought with her.

Mark raised a brow in curiosity, before freezing in his place in shock once he saw what it was.

Addison smiled, reaching into the box and pulling out a tiny orange kitten, no bigger than the size of a cup.

Cassie's eyes widened so much that they looked like they would pop out of her head at any given moment.

"I-Is that for me?" she asked cautiously.

"It is," Addison nodded, holding it out to her.

Immediately, Cassie jumped towards them and took the small cat into her arms, who instantly began to purr at the contact.

"You got me a kitten!"

"You got her a kitten?!"

"I got you a kitten," Addison laughed. "He was supposed to be adopted by a patient of mine, but they sadly didn't make it off the table. I couldn't just let the little guy go to the pound, you know?"

Cassie nuzzled it close to her chest, pressing kisses on it's forehead with a huge smile.

Mark looked at Addison incredulously, ignoring the adorable display in front of him. "You brought a cat into a hospital?!"

"Shh," Cassie scolded, holding a hand over the kitten's ears to shield him. "You'll scare him!"

Shaking his head in mock disappointment, he sighed heavily as a grin tugged at the corner of his lips. Mark honestly didn't think it was possible for Cassie to get any cuter, but alas, he was wrong.

"Adorable as he is, you'll have to take him home," Addison conceded. "Or at least put him in your locker until the end of the day."

Cassie held the kitten in the air, right above her face. "What do you think, little sir?" she asked in a high pitched voice. "Do you want to hang out in the locker room while mommy works? Hm? You wanna go in the locker room with a bed made of sweatshirts and lots of snackies? Yeah?"

"Make it stop," Mark deadpanned, looking at Addison. "Make it stop now."

The woman in question playfully rolled her eyes, turning back to a giddy Cassie. "So, am I forgiven?"

"I don't even remember why I was mad," she waved her off distractedly, tapping the kitten on the nose, earning herself a meow. "Also, off topic, but will you marry me?"

Addison laughed. "Like I said, this place is exactly the same."

☆

After running to the local store to get some cat food and a proper cage to put her unnamed kitten in for the day, Cassie watched from behind her chart as a nurse named Isabella shamelessly flirted with Mark. Of course, it's not as if it were uncommon for women to throw themselves at him; that wasn't the problem.

The problem, was that it looked like he was flirting back.

"Who are we glaring at?"

Cassie nearly jumped out of her skin when she heard George's voice from behind her. "Dude! Warn me the next time you're going to speak!"

"Sorry," he shrugged. "But who are you—" he followed her eyeline to Mark and Isabella, who were laughing way too hard to be normal at seven in the morning.

"Nothing," she said suspiciously, causing him to send her a look of disbelief.

"Why would you be... unless..."

After a few seconds, George let out a gasp.

Cassie physically cringed. "Don't—"

"YOU LIKE SLOAN?!"

"Shut up!" she hissed, taking hold of his elbow and dragging him into an on call room. All the while, his face was stuck with his eyes wide and his mouth gaping open.

"You like Sloan?" he repeated, much quieter this time, which Cassie was thankful for. "But he... and you... you like Sloan?"

Cassie sat on the bed in the room, silently cursing herself for being so obvious. "Look, George—"

"No freakin' way," he shook his head. "I knew it!"

"I— huh?"

"Everyone said I was wrong, but I knew it!" George clapped his hands together, pumping a fist in the air. "Yes!"

Cassie scoffed, smacking him in the arm while trying to hold in a grin at his actions. "I hate you. You know that, right?"

"No you don't," he scoffed knowingly, taking a seat next to her. He tilted his head in thought as he looked at her.

"What?" she said at his observant look.

"I've never seen you like this before."

"I've never been like this before," Cassie sighed heavily. "I've never even been in a relationship, for fuck's sake."

"Seriously?"

"Seriously," she groaned. "I don't know what I'm doing, Georgie."

"Look," George said. "Sloan isn't my favorite person in the world, and quite frankly, I think you could do better." Cassie gave him a look, which he promptly ignored. "But, I want you to be happy. I'd be naive if I said I hadn't noticed the way he stared at you, or talked about you for no reason—"

"He talks about me?"

"Cass."

"Right, sorry. Go on."

"If what you two have is real, then I say go for it. Even if you're scared, or if it doesn't end up working out in the end." George smiled softly, taking her hand in his own. "Life is short, Cass. Go out there, and live it before it's too late."

Cassie smiled at him gratefully, happy to finally talk about her feelings for once. She leaned into his shoulder, and he gave her a brotherly hug as he kissed her forehead.

☆

"Peterson, Lennon," Cassie snapped, gaining her intern's attention. "Feline report?"

Ollie smirked proudly down at his resident, his chin held high. "He is well nourished, well cuddled, and well loved. He did pee on my lap, twice, but that's to be expected in a kitten that young. Over all, he's in tip-top shape."

Rue crossed her arms over her chest with a frown. "I'm allergic to cats." Cassie narrowed her eyes threateningly. "But he is... cute. I guess. Besides, everyone who pisses on Ollie is automatically on my good side."

"Hey!"

"Oh, stop whining."

Ollie huffed under his breath. "You get peed on four times, and suddenly that's all your known for."

Cassie looked between them curiously, before snapping herself out of it with a shake of her head. "I don't even want to know. Anyways, make sure you two make more time to pet and feed him. I don't want him to feel neglected. Oh, but let him nap first. Otherwise he'll be a pill during the night."

Watching Cassie turn on her heel and walk away, Rue shook her head mournfully with a sigh.

"I'm allergic to cats."

Only a few steps away, George stood at the nurses station with his head in a chart when Cassie approached him.

"So, we're all set on the plan, right?"

George gave her a thumbs up, just as he noticed a certain someone coming their way. "Speaking of the plan..."

"Cass!" Mark smiled, before turning to George and nodding curtly. "O'Malley."

"Sloan," George greeted dryly.

Mark turned back to Cassie, who was looking up at him expectantly. "So, I was thinking, maybe we could talk—"

He cut himself off when George draped an arm around Cassie's shoulders, and Cassie smiled at him before leaning into his chest.

She raised an eyebrow at Mark, pretending that it was totally normal. "We could what?"

Mark looked between them confused as ever. "Uh, I thought that, um," he was once again distracted when George whispered something into Cassie's ear, and she giggled like a schoolgirl.

"Pretend I'm saying something really funny," George said lowly.

"I, uh," Mark looked between them. "Did you want to go to Joe's after work? To talk?"

Cassie frowned, over dramatically faking sadness. "Oh, I would, but Georgie and I were going to go to dinner tonight."

"Dinner," Mark repeated with a deadpan face.

"Yep!" she nodded brightly, pretending to be oblivious. "Anyways, maybe another time?"

"Uh, sure," he mumbled, watching her walk away with George's arm still around her. "O'Malley? Seriously?"

Cassie smiled up at George. "Do you think the plan is working? Is he watching us?"

He slyly looked behind him, and saw a fuming Mark Sloan glaring at him. "Oh, he's definitely watching you. As for me, I think I might need a 24/7 bodyguard for a few days."

☆

After Cassie stole Izzie's trauma surgery, all thanks to the power of the sparkle pager, she sat down for lunch with Addison and Callie.

Izzie passed by their table, not without sparing a glare Cassie's way. The latter just winked at her in return.

"She's no longer allowed in my apartment," Cristina said, stomping up to Callie. "So no more tea parties, or wine parties, or whatever you two have."

Callie furrowed her brows. "What? What are you talking about?"

"Hahn. She's completely unfair, and she refuses to teach me."

"She always teaches me," Cassie tilted her head. "I wonder why."

Cristina rolled her eyes. "Because you're McAngel. Everyone loves you. It's infuriating." She turned back to Callie. "Okay, I got in at Mass Gen, I got in at Johns Hopkins. I could have gone anywhere, and she won't teach me!"

"All right, look," Callie sighed. "Erica is a really good listener. She comes off harsh at first, but she's got a really good heart. So just tell her how you feel, okay?"

Addison and Cassie raised their eyebrows at the ortho resident, sensing what was going on.

"Tell her how I feel?" Cristina scoffed. "Well, I don't speak girl."

Callie watched her storm off, before turning back to the other two, who were smirking devilishly at her.

"Sorry about that. Did I mention I live with Yang now?" Finally, Callie noticed their faces. "What? Why are you looking at me like that?"

"Callie," Addison started. "Are you speaking the vagina monologues now? I mean, I'm all for it, okay? I think it's fantastic. Erica— I mean, she seems great. I really do like her, actually. I do, but are you?"

Callie looked at her as if she were crazy. She turned to Cassie for help, who simply pointed to the other woman in agreement.

"You want to know if Erica and I are a-a-a couple?" Callie stuttered. "Because I defended her to Yang?"

"No," Cassie shrugged obviously, popping a grape in her mouth. "Because you seem like a couple. A really happy couple, at that."

"Okay, that's... that's... that's just... that's... that's insane is... is... is what it is. I'm—"

"Callie."

"I like penis!" she shouted, gaining a few odd looks. "I mean, I'm a huge, huge fan of penis."

"So am I, but that doesn't mean that I don't like girls as well," Cassie said nonchalantly.

"You like girls?" Callie asked surprised.

"Yeah," Cassie nodded, as if she should've already known. Addison gestured to her in a similar manner.

"Yeah, maybe you're bi, or pan, or whatever."

"You know, people who identify as bisexual actually make up more than half of the LGBTQ plus community," Cassie supplied. "There was actually a study done a few years back, that showed how bisexual people are often more afraid to be open about their sexual orientation, and if they are openly bisexual, they're more likely to face bias and a distinct lack of support from their peers."

Addison nodded. "We won't judge you, Callie, as long as you're happy."

Callie, though secretly deep in thought, laughed stubbornly. "That's sweet, but Erica and I as a couple? I don't— no, that's never going to happen. No way."

☆

After lunch, Cassie joined George in the lobby. "How's operation make Sloan jealous going?" he asked her with a smile.

"No idea," she replied. "Good, I hope, I'm just worried that this is a bit counterproductive. Also, no offense, but pretending to be into you is doing absolutely nothing for my gag reflex."

George noticed Mark watching them out of the corner of his eye with a hardened expression on his face. Unknown to any of the three, Addison was watching as well.

"I already told you," George said. "It will make him realize what he's missing. You're amazing, Cass, and he would be lucky to be able to be with you. Think of it as a reality check."

"Fine," she sighed. "Ooh, he's watching! Quick, act like you want to have sex with me."

George winced. "Ew."

"Okay, rude."

"You just said— you know what, nevermind."

In a painfully awkward manner, George leaned in, trying to visibly show that he was interested in her.

Mark glared daggers at them from down the hallway.

"This feels very, very wrong," George said quietly.

"It does," Cassie agreed through a smile and gritted teeth. "Just a little bit longer, and then we can both pretend like this never happened. Deal?"

"Deal."

Only seconds later, Addison came up behind Mark with her arms crossed.

"Are you an idiot, or are you just dumb?"

Mark whipped around to face her, prying his eyes of the girl he loves. "Excuse me?"

"I know you told me that you liked her, but that was months ago, Mark. At first, I thought you got over it, but clearly that's not the case." She looked at him in confusion. "You still haven't said anything?"

"I don't like her."

Addison froze, pausing for a long moment as she studied him. "Oh, god, Mark. You love her, don't you?"

"It's complicated."

"How so?"

He thought for a moment. "I'm scared, okay?" Addison gave him a look to continue. "It's just, what if when I finally tell her how I feel, and she doesn't feel the same way? Or what if everything changes, and I lose her for good?" He slumped against the wall. "I can't lose her, Addie."

"But you're hurting," she said sadly.

"It's worth it," he replied immediately. "It's worth it, as long as I can keep her in my life. Even if she's with O'Malley."

Addison laughed at the absurdity of what he just said. "O'Malley? You seriously think they're together?"

"Well, they seemed pretty together the last time I saw them," he grumbled.

"She's trying to make you jealous, obviously. And clearly, it's working."

"Make me jealous? How would you know?"

"Because on my way over here, I quite literally heard her say, 'Is it working? Does he look jealous?'."

Mark stared at her for a moment. "No, you're lying."

Addison watched as he walked away, glaring at George the whole time. "Do I have to do everything myself?" she said under her breath, already coming up with a plan to help the two most stubborn people alive admit how they feel.

☆

Before heading home that night, Cassie sat patiently in an on call room that Addison had paged her to, with her kitten sleeping soundly in it's carrier on the bed.

Why she'd been paged, she had no idea, but she secretly hoped Addison was going to give her another cat.

So, when the door opened and Cassie looked up expectantly, she assumed it would be Addison who had entered.

Alas, things don't always work out as one would expect.

"Mark?" Cassie frowned, immediately standing up after making sure her kitten didn't wake up. "What are you doing here?"

"Addison paged me," he shrugged, his brows furrowing in confusion. "Wait, what are you doing here?"

Cassie leaned against the wall, playing anxiously with a loose thread at the bottom of her sweater, having already changed back into her regular clothes. "Addison paged me, too."

Suddenly, the previously open door slammed shut, to both of the doctor's surprise. "I'm sorry, but I had to," they heard a familiar feminine voice call from outside of the door.

"Addison?" they chorused, sharing an odd look with each other.

"There are clearly words unspoken between the two of you. I've been here for less than twelve hours, and quite frankly, I'm already tired of the longing looks," she continued. "I'm not opening this door until you figure it out, so don't even bother trying to leave."

Cassie rolled her eyes. "I don't have time for this," she grumbled, though really she was nervous about what might happen.

"Oh yeah," Mark scoffed. "Can't be late for your date with O'Malley."

"What date?" Cassie frowned, before she remembered the plan. "Oh, yeah, my date... with George. Totally."

Mark saw right through her. "There was never a date, was there?"

She huffed, shaking her head in defeat. "No offense to him, but I'd rather get hit by a bus."

"Then why would you..." Mark paused, as a cocky smirk took over his features. Cassie winced at the expression. "You were trying to make me jealous, weren't you?"

"No! I-I wasn't—" Cassie stuttered, before raising her voice and pointing an accusing finger at him. "You were trying to make me jealous too!"

"What? No! When?"

"When you and that Isabella girl were flirting this morning," she said with narrowed eyes. "I mean, she's pretty. I don't blame you."

"Isabella?" Mark laughed. "I was helping her make her ex girlfriend jealous, not you."

"Girlfriend?" she repeated, taking it all in. "Oh. Her girlfriend."

"Yeah." he tilted his head, thinking about it for a long moment. "Wait, you were jealous?"

"No." Cassie raised a brow back at him. "Were you?"

"No."

"Good."

"Good."

"Fine!"

"Fine!"

They stood across the room from each other, both of them mirroring the other's defensive body language and breathing heavily. Mark watched as she shuffled her feet slightly, thinking of something to say to make the situation less painfully awkward.

Cassie was perfect, he thought. Her laugh, her kindness, her stubbornness, her generosity, her unwavering ability to make someone feel comfortable, the way her face relaxed when she slept, how her eyebrows furrowed when she concentrated, how she always smelled like a mixture of honey, old books, and coffee. Cassie was perfect.

He couldn't hold it in anymore. He couldn't pretend like a day, no, a moment, went by that he didn't think about her. He couldn't act like he was okay with the fact that she didn't know how much he cared. He couldn't go on like this. He had to say it, and he had to say it now.

"You know what," Cassie scoffed suddenly, running a hand through her shoulder length hair. "This is ridiculous, Mark! I'm over it! So I'm just going to leave, and we can pretend this conversation never even—"

"I love you."

"—happened!" Cassie finished her rant, before freezing in place. She opened her mouth to speak, but all that came out was a strange sound from the back of her throat. Staring at Mark as if he'd grown two heads, she spoke slowly as her heart began to pound in her chest. "I'm sorry... could you repeat that?"

Mark smiled softly down at her, moving forward so they were less than a foot apart.

"I love you," he repeated. "I love you, I love you, I love you."

Cassie stared up at him, dumbstruck. "You love me?"

Mark nodded, never more sure of anything in his entire life. "I love you. God, you're everything to me, Cass. I would rip my heart from my chest, if it meant yours could continue to beat." He extended an arm towards her, tucking a stray hair behind her ear. Cassie was still frozen in place. "I love you. And you don't have to say it back, but—"

"I love you too," Cassie blurted, before her eyes widened in shock at her own words. "Fuck, I just said that out loud. Oh god, I can't believe I actually—"

She was cut off by his lips meeting her own.

In the blink of an eye, his hands went to both sides of her face as she hesitantly wrapped her arms around his neck. When she pulled away a few seconds later, she gave him a happy — yet slightly petrified — smile, which he returned with a huge grin. Once again, he kissed her, unable to keep from smiling against her lips. Cassie was about ninety percent sure that there were literal fireworks going off in the background.

They were interrupted by a soft meow coming from across the room.

They pulled apart with a laugh, their foreheads resting together. "I love you," Mark whispered once again against her lips.

Cassie let out a small snort as she backed up a few inches, but kept her arms around his neck. "Yeah, you mentioned that, once or twice."

Mark playfully rolled his eyes. "Shut up. You liked it."

"Don't you mean loved it?" she asked cheekily, before tilting her head up at him. "I love you too, you idiot."

He shook his head at her, still grinning from ear to ear. "You're insane."

"So I've been told," she shrugged, happily realizing how easily they fell back into their old ways.

Everything was perfect, until a dark thought passed through Cassie's head, prompting her to let out a gasp.

Mark frowned. "What is it?"

Cassie looked up at him in alarm. "Derek."

His genuine smile quickly turned into a look of sheer panic. "Oh, my god," he said worriedly. "He's going to kill me."

"I mean, it can't be that bad—"

"He's going to skin me alive," Mark said matter-of-factly. "Remember when Addison's brother checked you out at the pool party? He gave him a black eye and a broken nose, and he didn't even talk to you!"

"Well we've done a lot more than talking," Cassie frowned, thinking it through completely. "Yeah, he's definitely going to kill you."

As Mark gazed at her swollen lips, which were opened slightly in worry, a smirk slowly took over his face.

"Eh," he shrugged carelessly, pulling her in closer by her waist and causing her to let out a surprised yelp. "Screw him. You're worth it."

author's note —
*clears throat* ahem.

AHHHHHHHHHHH
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