Hypothesis 1: A light suck will not leave a mark underneath the supersuit if delivered to the chest.

Variant: Using a spot on Ladybug's suit

Test:

Once they'd found a rooftop secluded enough, they began to consider all their options; starting with position. Should she sit up? Lay down? Should he lie down and she could hover over him? Or maybe they could sit next to each other? After a trial in a few rather compromising positions, they'd decided that she would lie down and he would position himself over the spot.

Which brought them to the next issue?

It had taken herself and Chat a lot longer than anticipated to choose which spot he'd 'hickey'.

Lower arms - too noticeable; upper arms - too weird; neck - maybe next time? It was only during this so-called 'experiment' that she realised the extent of where her spots were actually positioned. The ones around her chest were pretty much on it; the ones around her stomach and legs were in a far too intimate area for her partner to be sucking on, which didn't leave them much of a choice.

They looked over and over, checking each spot and listing the pros and cons. Chat Noir's instance of marking her ass affected her a lot more than she would have liked to admit, however after a quick discussion it was determined inappropriate for the experiment, which only left the spots on her upper chest area.

So they had decided on the spot, so now they needed to work on their hypothesis. Ladybug had sat by watching as Chat paced back and forth across the rooftop wondering how to set this up.

As always she couldn't stand his overthinking and was quite sure the words 'come and suck me here' left her mouth as she pointed down towards her chest, not a moment she would ever be proud of.

It was the first time she'd ever seen her kitty lost for words, the stuttering and stumbling a sight to be seen, because this was not superhero Chat Noir, this was a guy getting close to breasts for the first time. As he bent down towards her chest and fixed his lips securely there, she couldn't help the slight gasp leaving her mouth. Not only had he never been near breasts, but no one had ever been near hers either, especially a boy. Maybe Chat had landed there a couple of times during battle, but that didn't count. Right?

Anyway, after a lot of fumbling and giggling (and a rather embarrassing groan from Ladybug), they believed they had done what was needed, and, maybe, Ladybug had allowed him to suck a little longer than necessary. But time wasn't a factor, right?

Finally, saying an awkward goodbye, they both left the rooftop and headed home, Marinette none the wiser to if it had worked, but carrying a whole new barrage of confusing feelings for her partner which was ready to explode.

Findings:

When Marinette woke up the next morning she couldn't help but notice the dull ache around her chest area, situated just to the side of her left bra strap.

Walking over to her full length mirror she pulled her pyjama top strap to one side and viewed the mark. Oh yes, it had most certainly worked, though the aching didn't seem to match the depth in colour. It was barely there.

"That's oddly disappointing," she announced to her reflection before continuing getting ready to meet the gang, making a mental note to tell Chat that maybe next time the suck would need to be harder. She took a picture of her chest, before examining her first ever hickey. A hickey given to her by Chat Noir...now there was a turn out for the books.

Checking the time she realised there was less than 20 minutes until she needed to meet the others in the park—they'd planned a picnic and Marinette had been trusted with bringing the after lunchtime treats. Running around, and quickly placing on her clothes she headed out of the bakery and into the park where Alya, Nino and Adrien were sitting waiting for her.

"A-A-Adrien, I didn't know you were coming?" As she stumbled forward, shocked by the appearance of their sunshine friend, tripping over the edge of the prepositioned picnic blanket and sending the tray of treats flying into the air.

No, no, no, no!

Closing her eyes tightly, she prepared for a less than flattering landing, when instead of the sharp points of rocks, her body landed on something soft. Soft and, from the smell of it, delicious.

Opening her eyes, she noticed her head was firmly tucked under Adrien's chin and his arms secured around her.

Oh no, no, no, no, no! She'd fallen on top of Adrien! Breathe Marinette, breathe!

Springing off him as though he'd shocked her, she attempted to fix her clothing, straightening her top first before moving to her trousers.

"You must be sorry, I mean, I'm sorry. For falling for you - on you - for falling on you. Because I don't fall for statues - models. I mean you're, you know, and maybe a - picnic blanket. Yes, picnic blanket, great thinking Alya. When having a picnic you always need a picnic blanket, to stop ants and...bugs." Turning sharply and withholding the want to scream, she looked at Alya who was giving her a pitiful expression.

'I know,' Marinette mouthed back, turning once more and slumping down on the spot, eyes firmly trailing the gingham pattern of the blanket.

Oh dear!

"You sure you're okay dudette?"

"Peachy," she said, reaching for a croissant at the same time as Adrien. She should have stayed at home, this was becoming worse than the wax museum incident. Actually no, nothing was worse than that day.

"You have it." Marinette used her hands and pushed the delicacy towards him. "I have germs...on my hands. Can't eat without sanitising them." She swung an arm in front of her, attempting an upbeat approach only to remember not only had she just touched Adrien's hand, but his food as well and told him she had germs.

Holy mackerel!

"Um - okay - thanks, I think." Adrien looked at the food before looking back at Marinette, her smile imitating one Ronald McDonald would be proud of. Slowly, he raised the croissant to his mouth and took a bite, eyes never leaving hers and a look of slight panic on his face.

"Marinette, seriously, are you sure you're okay?"

"Yup, why wouldn't I be?"

"There's, like, a pink mark on your chest." She looked down towards where Nino was pointing and noticed her top was a little crooked, and showing a whole lot of hickey.

As she tried to straighten her top she could feel both Nino and Alya staring at it, her subconsciousness knowing full well her friend was analysing it. Luckily, Adrien chose that exact moment to choke on the germ infested croissant taking the attention away from Marinette.

Conclusion:

A light suck will leave a mark on the human body; however, the mark will be equivalent to a bruise and not a hickey. In other findings, don't tell friends you have given them food with germs. Results: possible death of friend and crush.

Evaluation:

Adrien couldn't stop thinking since the afternoon's revelation. It had plagued him from the moment Nino had pointed it out until he'd returned home. Marinette had a mark exactly where he'd attempted to leave one on Ladybug the previous night. It could have been a coincidence, after all Marinette was a very clumsy girl. But he knew those spots like the back of his hand. He could label every single position and that bruise was on one of Ladybug's spots; he was almost 100 percent sure of it. When patrol time came, Adrien couldn't help springing into action quicker than usual. He needed to know.

"So? Did it work?" Chat Noir landed next to Ladybug on the rooftop, eager to find out if he'd created the mark that had made him choke on his croissant.

"Nope. Sorry Kitty. It seems if you want to leave a hickey on me you're going to need to suck a little harder."

"There was no mark then?" he inquired further.

"Not really. I would barely call it a blemish."

A blemish? A faint mark? A mark which could be seen as a bruise? This had to be right. He must have finally found her. After all these years he'd found his bug all thanks to the hickey.

"Damn," he sighed in mock despair.

It was too late now, he knew. He knew that Marinette had a mark exactly where he'd left a love bite on Ladybug last night. He also knew he had no idea what to do with the information.

"So do we go onto hypothesis 2?" he asked, his heart racing with these new details. Though he wasn't sure whether he should tell her or not, he was quite sure he wanted to take what he could while he could and he wanted her to hickey him.

"Yep. Time to swap kwamis, Bugaboy."