A/N: A huge shout-out to catastrokey, bcnedrah and brooklynxmagic on tumblr for some ace dialogue inspiration!

"By the Angel!" Alec yells, his eyes wide and his hand reaching for the bow that isn't there because he never usually feels the need to protect himself when he's around Magnus.

"What's wro- oh, look who nobody dragged in but somehow ended up inside anyway." Magnus' internal shields are up in a heartbeat as his expression changes from amused to protective.

Azazel smirks at him. "I knew I could always count on you for a warm welcome, nephew dearest."

Magnus scoffs. "You can't expect any kind of welcome after you forced me to leave behind my own body, uncle dearest."

His words have never been more scalding and some part of Alec files this under 'badass things his boyfriend can do' even though he really should be focusing on the second greater demon their home has been annoyed with rather than making a note of how much he loves Magnus.

Instead of offering any kind of apology, Azazel shrugs. "I am merely the messenger this time around."

Alec frowns. "Who needs a greater demon as a messenger?"

Fighting the urge to roll his eyes at the naivety in that question, Magnus throws Alec a pointed look and gestures to the bookshelf. Realisation dawns on Alec within a millisecond and he blushes, clearly embarrassed by his deductions, or lack thereof.

"If you're the messenger, shouldn't you have a message for us?" Magnus asks, practically sensing Alec's embarrassment and wanting to divert the attention from his flushed shadowhunter.

Azazel's eye roll would win the Olympics if eye-rolling were a sport. "I have an invitation."

Both Magnus and Alec step closer to one another, Magnus still in front. Azazel takes this in and raises a single eyebrow. "It's a very innocent dinner invitation."

"Since when does Asmodeus invite shadowhunters for dinner?" Magnus asks. "Or do anything innocently, for that matter?"

"Wait, Asmodeus. As in, my father-in-law? The same father-in-law who destroyed our bookshelf? He wants to have dinner?" Alec blurts, clearly not fully awake – or just traumatised by his first meeting with the in-laws.

To his credit, Magnus barely reacts, replying, "Technically, It was the company he attracted that destroyed our bookshelf. And, darling, how many other fathers-in-law do you have?"

"Oh, Lord, save me from this-" Azazel holds up a hand- "that's the wrong kind of being to pray to, pardon me."

Magnus has never seen Alec look so utterly bewildered and out of control so he laces their hands together and turns back to Azazel with a nonchalant glare. "Either get to the point or get out, would you?"

"Touchy, are we?" Azazel retorts but then nods. "Your presence in Edom at midnight is required."

"That's not how invitations work," Alec says, finally somewhat in his senses.

"They are if you're my father," Magnus mutters and waves a hand. "You can go now."

"I will, but not because you asked me to, but because I cannot tolerate this impolite behaviour and I would much rather converse when the both of you are a little more tolerable." Instead of announcing his departure like most beings would, he vanishes on the spot, with no warning whatsoever.

"Magnus?" Alec asks as soon as he's gone. "What exactly just happened?"

"I believe it's some sort of ulterior motive in action, Alexander, but not to worry!" Magnus chirps. "As long as we ignore my father the whole time, everything should go smoothly."

"What?"

"Obviously just seeing you wasn't enough for my father, so we've been ordered to go and meet him again."

Alec's expression mirrors the disbelief in his mind when he licks his lips as if saliva can give him the strength needed to speak. Magnus waits patiently as Alec takes a deep breath before deciding on his question: "Are we meant to wear matching suits?"

"Since when did fashion become a priority to the same Shadowhunter who wears the same t-shirt for a week?"

"Since I have to make a good impression in front of the father of the warlock embodiment of fashion itself!"

Alec's panic is clearly genuine because his ability to articulate sentences is usually a little less repetitive than that, which Magnus can't help but find both endearing and hilarious.

"I'm almost insulted you assume my style is based on anything but my own creativity." Magnus plants a small kiss on Alec's nose – a gesture that never fails to make him smile – and smirks. "It's probably better for you to go looking as different to me as you can, to be honest."

There's a small smile on his face and miniature fireworks on the tip of his nose but Alec still can't even remotely calm down, the thought of willingly going to Edom making him slightly nauseous. In fact, he's still out of it until something falls around him, causing him to blink and slowly realise Magnus has gone. And left a shower of glitter going above his head.

Groaning, Alec steps to the side, only for the glitter to carry on falling around him, recycling itself to back above his head just before it hits the floor.

"Magnus!"

"Yes, sweet pea?" Magnus draws from behind him - so he has to spin fast enough to give a regular mundane whiplash - as if he'd been standing there all along. Which isn't totally out of the question, since Magnus seems to enjoy staring at Alec even though he doesn't really understand what he has that's worth the attention, but that's another matter.

"Cut it out!" Alec whines.

"Cut what out? Honestly, you'd think a Shadowhunter would know to be more concise..."

"Magnus, I will break up with you."

"Will you really?" Magnus' eyes have ever looked so sly.

No.

"You doubt me?" If anybody could see his smirk, they wouldn't recognise him.

"Yes. Yes, Alexander, I do."

"Already? But you haven't even proposed."

Alec's heart is in his throat because did he really just say that without thinking? He might not know how to control his oral filter but he does know how to go along with things so he can easily fold his arms and raise an eyebrow as if he isn't totally freaking out on the inside.

Magnus laughs and snaps his fingers, the glitter vanishing as quickly as it had started to rain, making Alec grin smugly. He manages to retain said smugness right up until Magnus creates the portal for them to go to Edom, at which point his confidence fizzles.

"Magnus, I can't do this."

"And the head of the New York Institute can't be in a relationship with the High Warlock of Brooklyn but here we are, mm?"

Alec breathes, taking Magnus' outstretched hand and stepping through the portal. After recovering from nausea that might be from nerves and might be transportation side effects, he nods to Magnus, the two of them starting to walk. They don't really have to go far, just a little distance where, despite the barren landscape, a rather lavish house stands. Well, it's more like one large room, as Alec discovers once they walk through the doors.

"Magnus!" Asmodeus booms instantly, smiling wolfishly.

"Father."

Alec's tongue refuses to work so he just nods, hoping he's not being impolite. How is he meant to know what kind of standards a prince of Hell has anyway?

"Oh, sit down already," Azazel mutters, rolling his eyes from where he's sat at a small, rectangular table.

Magnus pulls Alec to one of the longer sides, sitting so Magnus is in between Asmodeus and Alec and the two of them are opposite Azazel. Asmodeus smiles strangely as he settles at the head of the table, gesturing to the food in front of them. "Help yourselves."

Even Azazel seems a little shocked, choking on his wine.

"Alright, we're here, now what do you want?" Magnus asks.

"Why can't I just want to have a nice dinner with my son?"

Alec watches Magnus snort in amusement. "You wouldn't know how to be nice even if it was a part of your DNA so-"

"How can we help you?" Alec interrupts, trying his best not to panic.

Three sets of eyebrows lift up in surprise before Asmodeus can recover and shoot Magnus a pointed look, then turn to Alec. "I'd like a word with you."

"You wish!" Magnus scoffs, frowning, shifting closer to Alec.

As euphoric as that makes him feel, Alec knows Asmodeus won't give it up until he gets his way so he kissed Magnus' cheek and winks. "I'll be quick."

After a second, Magnus nods and squeezes Alec's hand before standing and walking out of the room, Azazel doing the same. He watches them leave, only slightly worried, eventually turning to Asmodeus with the best smile he can manage.

"I have an offer for you, Shadowhunter."

"What kind of offer?" Alec asks, both curious and dubious.

"One regarding your little argument with my son."

Argument? Alec doesn't waste time wondering how Asmodeus knows about their argument, choosing instead to wonder what Asmodeus can do about the contents of Magnus' box. He can't figure out what he's missing until…

"You mean…?"

"Magnus' immorality, yes," Asmodeus confirms, a glint in his eyes.

"You're not taking away his immortality, I already know that's too high a price to pay." Alec doesn't even think before saying that, knowing that Magnus becoming mortal now would be a disaster and a half and the last thing they want is to cause either of them more pain.

Asmodeus, however, seems unfazed. "I wasn't referring to taking away his immortality…"

Alec's eyes widen. There's no way to avoid it, the prospect of being able to spend a forever with Magnus too beautiful for him to stay professional. He can tell that's the desired effect because there's an air of victory around Asmodeus immediately.

"What's the price?" Alec asks. He might be sentimental and hopelessly in love but he's not entirely naïve.

"A favour."

"A favour?" he echoes, not believing it.

"Exactly. A small favour, just the one, in exchange for immortality." Asmodeus smiles, but this time it's scarily warm as if this really is some kind of gift and not the way to achieving an ulterior motive.

"I…"

He doesn't know.

"I need to talk to Magnus."

Asmodeus, having anticipated such a reaction, simply waves a hand as permission. Alec is out of his chair immediately, all but sprinting to Magnus and stumbling out of the door, where Magnus is waiting with an anxious look on his face.

"Magnus, he…"

"I know, Alexander, I know. And you can't. You can't, darling, it's not worth it."

"But, Magnus, it's not that bad of a price to pay."

Shaking his head, Magnus takes Alec's hands. "You don't want to owe my father a favour, especially not when he's just given you immortality."

Beside them, Azazel clears his throat. "This is awfully sentimental but I suggest you hurry up and make a decision before he changes his mind." And, with that, he's gone, walking back inside.

"He always was my most helpful uncle," Magnus mutters.

Alec exhales, both in amusement and determination. "Magnus, I have to. I don't care what I'll have to do."

"Alexander… This isn't like losing a bet to your siblings, this is Asmodeus having power over you for all of eternity. I don't want that for you."

But Alec is stubborn by nature and, worse, he's in love.

Before Magnus can say anything else, Alec has pulled them inside and is already nodding. "I accept."

Azazel chokes on his wine a second time – he might as well learn not to drink it when Alec is around – just as Asmodeus beams. "Wonderful!"

"Alexander!" Magnus looks at him with a mixture of shock and concern, primarily the latter.

Alec wakes up to Magnus' golden eyes.

"What just happened?" Alec groans, slightly alarmed by the worried rage in his boyfriend's eyes.

"Welcome to immortality," Magnus murmurs, pulling Alec into a sitting position and throwing his arms around him. Alec blinks, then hugs Magnus back, seriously confused as to what he's missed.

He then notices the newfound energy in his soul and his eyes widen as he gasps, "Magnus?"

"You can be my new box," Magnus whispers in his ear and Alec chuckles, then looks up to see Azazel grinning happily at them. He'd be concerned with the devilish look in Asmodeus' eyes but he's too wrapped up in the reality of being immortal to care about anything else right now.

Time melts into their embrace, the two of them still reeling from the turn of events but happier than they've ever been. Nothing matters, not Edom, not Lilith, not oxygen, as they relish their unprecedented happiness, Alec still dimly wondering why and when he'd passed out and why Magnus' eyes had revealed themselves, but he now has forever to ask about that.

Someone claps.

It's Asmodeus, naturally. Alec and Magnus reluctantly pull away and stand before the greater demon, matching questioning looks on their faces.

"A word, if you will?" He drawls.

Alec nods. "Of course."

He sees Azazel moving towards Magnus after he follows Asmodeus to the side of the room, where he's met with a sly look. "I have my favour to ask you."

"Of course," Alec replies without missing a beat, "I'll do whatever you need."

"Break up with Magnus."

Alec's heart, now immortal or not, stops beating for a second.

He'd done all of this, risked it all, just to be with Magnus... and Asmodeus, the one who'd helped to make it possible, is asking him to end their story before it can truly blossom? He knows he should have foreseen something like this happening, he knows Magnus had warned him, but he'd still hoped that everything could just go smoothly for once.

In and out.

His breathing is deafening as he processes the statement, trying to comprehend the gravity of his situation and unravel the consequences so he can figure out a way to get through them without breaking his heart, or worse, breaking Magnus' heart. He has to find a way, he tells himself, he has to find a way to fix this dilemma before anyone, namely Magnus, can sense its existence.

Inhale and exhale.

He bites his lower lip, ignoring Asmodeus' smouldering gaze, and lets his eyes close as he thinks it through. He knows he won't be able to cope without Magnus, he can feel the pull to Magnus in his bones, and there's no way he can live forever without the comfort of his first and only boyfriend beside him. Being with Magnus isn't a choice for him anymore, it's a way of life, so he has to figure something out before his world crumbles.

"Okay," he says eventually, opening his eyes with a strong smile.

"Okay?" Asmodeus echoes, his confident arrogance fading to shock. Genuine shock. The kind of shock you would never expect to see on a greater demon.

Alec grins. "Yeah, okay. That's fine. I'll go do it right now!"

He's aware of Asmodeus' conflicted gaze on him as he walks back to Magnus. He grabs Magnus' jacket lapels and gently smashes their lips together before pulling back with a small wink.

"Magnus, I'm breaking up with you," he says, trying to keep his voice as neutral as possible.

Magnus blinks at him, still reeling from the kiss and startled by the wink. He opens his mouth, his eyes glittering with scepticism and pain, but Alec shakes his head, not wanting to give Asmodeus the satisfaction of seeing either of them distraught.

"Right, I think that settles everything. Unless there's something else you want, Asmodeus?" Alec can't be bothered to even try and sound polite so he just smiles broadly, internally laughing at Azazel's dumbfounded expression.

"Alexander?" Magnus asks quietly, his voice full of question and trust.

When Asmodeus shakes his head, Alec turns to Magnus and waves a hand. "Care to make a portal back?"

This time, they go through separately, Magnus watching as Alec strides though and then hesitantly stepping in after him. The second the portal closes, Alec pulls Magnus into a hug, breathing deeply. Alec's guilt courses through him like wildfire as he feels how tense Magnus is but he'd had no other choice.

"Alexander?" Magnus repeats, unable to say anything else with his head whirling faster than light can travel. It takes him a few minutes but he finally works up the courage to say, "You just broke up with me."

"Your father asked me to."

"You seem... calm?" Magnus' eyebrows furrow in confusion.

"Of course I am. Now, if you'll allow me, I'd like to get back together with my ex."

"Alexander, aren't I your ex?" Magnus asks after a pregnant pause, small embers of hope lighting up in his eyes.

Alec grins. "Exactly."

Magnus laughs, his tension melting away like ice in a desert, and kisses Alec, then taking his hands and grinning. Alec grins back instantly, glad Magnus hadn't misunderstood. "So, this time around, will you be my boyfriend for as long as immortality can offer us?"

They're both laughing and they're both nodding – even though Alec has no reason to since he'd asked the question, but he's just that kind of awkward – and they're both more than a little bit giddy with excitement.

Said excitement remains undisturbed for the following three minutes, after which two greater demons appear in their kitchen. At least it's not the bookshelf this time, Alec thinks.

"What did you do?" Asmodeus growls, probably having sensed Magnus' extremely fluctuating emotions.

Magnus smiles and swings their connected hands as he says, "You really should learn to be more specific."

Azazel snorts, clearly impressed, as Asmodeus' rage turns into disbelief and back to rage again. "How dare you betray our deal?"

"I didn't. I broke up with him, just like you asked me to-" Alec clears his throat- "but you never said we couldn't get back together."

Silence reigns.

Its reign ends when Asmodeus blinks and darkly mutters something under his breath, pinching the bridge of his nose as if that can help him, as if anything can help him, which it can't. He looks to Azazel for help but finds none, the other greater demon laughing quietly.

"Azazel!" Asmodeus chides, "Why are you supporting this?"

Azazel shrugs. "Hoping to outwit the High Warlock of Brooklyn and the head of the New York Institute was never a reliable idea, brother."

"I only needed to outwit the stupid Shadowhunter," Asmodeus grumbles.

"Be careful who you call stupid, father," Magnus warns, his voice cold and sharp but burning with ire.

Asmodeus looks up at that, glancing over Alec once again. "And what exactly makes you so special?"

Alec grins. He wants to say something satirical or sarcastic but if Asmodeus is anything like Magnus, there's not much point. Instead, he turns to Magnus and smiles. "I'm in love with your son."

Azazel whistles. He also immediately stifles it because Asmodeus growls at him and glares at the now-reunited couple. "You might have won for now but I have time on my side and I will win this."

"Yeah, and so do we," Magnus scoffs, "so good luck with that."

Their fridge disappears as Azazel creates a portal in its place, Asmodeus marching through with irritation radiating from his form and Azazel winking at them before following, not even trying to hide his bemusement.

"Next time you break up with me for the sake of loopholes, how about giving me a little warning?"

Alec shakes his head. "Nah, that would lose the authenticity, wouldn't it?"

Magnus' jaw drops open and he stares at Alec in disbelief. It's okay, though, because Alec wipes that disbelief away when he kisses Magnus' forehead, a soft, apologetic smirk on his face, an expression that wouldn't be possible for anyone else to display.

"You're lucky I love you," Magnus murmurs but, to Alec, it's as loud as love itself, if not louder.

"I guess that means we're both lucky, right?" Alec whispers back, knowing his face is flushed and his smile is idiotically wide.

"Unfortunately for Asmodeus…" Magnus agrees, beaming.

Asmodeus may be the ruler of Edom, powerful, sly and feared by many, but nothing can defeat the love between Magnus and Alec. Their love is a force to be reckoned with, one that can withstand the strongest of attacks and the most unscrupulous of plots, constantly reinforced by their adoration and appreciation for one another. And now that they have immortality on their side, the universe doesn't stand a chance against the power they wield without even trying or the power they can unleash, almost effortlessly, within a heartbeat.

Sorry it's like a week late, I can never post to wattpad on time... Not that anyone on wattpad even knows I exist... But yeah, love y'all!