Bellamy discovers Clarke's public sex kink in honestly the most predictable way.
It's late on a Thursday night, and he's in the library, looking for the most obscure book on the most infuriating topic he's ever had to write a paper about. He's normally all about history and Latin and all that jazz, but when he decided to take Latin in History, he thought it would be more about the actual history than the Latin. So he's in a section of the library that looks like no one's been there for years, trying to find a book about Proto-Romance sound changes, when he sees Clarke.
He knows Clarke, in the sense that she's friends with his sister and they see each other in that context sometimes, and whenever he leaves he has to remind himself that she's Octavia's friend and he's not allowed to go there. He knows Clarke, in the sense that she's also taking Latin in History this semester and they grumble together sometimes, even if she is actually in it for the Latin.
He knows Clarke, in the sense that he's completely floored by the realisation that she's sitting in a corner with her eyes closed, one hand in her pants and the other disappearing up her shirt. Of all the situations he would have expected to run into her in, this is definitely not one of them. It's not even that she's in public, where anyone could just walk in—like he just did—but the fact that he generally associates her with Octavia, and this isn't something he wants to think about in the same sentence as his baby sister.
His dick twitches, however, noting that it's definitely something he wants to think about in general.
Clarke makes a soft noise, and he starts out of his thoughts, letting out an involuntary yelp. Her eyes fly open, going wide when she sees him staring at her with his dick straining visibly against his jeans.
"I, um—" she starts, at the same time as he says "Sorry, I was just—" she laughs, breaking the tension a little, but makes no move to withdraw either of her hands.
"I was going to say as you were," Bellamy comments, finding his words, "but that seems a little creepy. I'll just, uh... come back later. Fuck Latin, anyway."
He's already turning away, trying his hardest to commit to his memory the image of Clarke with her cheeks slightly flushed and her hair falling out of its braid, when she tells him to wait. "You could, uh," she says, clearly trying to find the right way to phrase whatever she's trying to say. "You could stay," she says finally. "I wouldn't mind."
It takes Bellamy a moment to process this. "You mean like, to watch?" he asks, not knowing which answer he's hoping for. On one hand, he feels like he could plausibly watch Clarke get herself off forever and die happy when he eventually wasted away from starvation, but on the other... his dick twitches again, and god, he's dying to touch her.
"Do you want to just watch?" she asks, like she already knows the answer.
"Fuck no," he breathes, sitting on the floor beside her and pulling her into his lap. She finally removes her hands from her body, tangling them in his hair instead as she kisses him, and he sends up a silent prayer of thanks for Latin in History and fucking Proto-Romance sound changes.
There's a moment or two where he's entirely too aware of the fact that they're in the main campus library, but then she moves her hips in his lap, and he honestly couldn't care less if the dean himself walked in on them. He's resolutely avoided thinking about Clarke like this since he met her, knowing that she's Octavia's friend, but her tongue is in his mouth and her small hands are tugging at the hem of his shirt and she started it, so he figures it's safe to let her divest him of his shirt, to do away with hers as well, to unhook the bra that she's already half hanging out of after her earlier exploits.
She sighs when he breaks the kiss, but he ducks his head to tongue at her breast, and she sighs again, in pleasure this time. Her hands explore the planes of his back, and he shivers when she ghosts over the nape of his neck. She soon grows bored of his back, though, and her fingers drift around to find the button of his jeans. They've managed to get rid of both their jeans through a series of frankly impressive manoeuvres when he realises—"Shit, I don't have a condom."
"What kind of boy scout are you?" she teases, but she's already pulling his boxers over his hips and taking him in her hand. "It's okay," she says, and lowers her mouth to his dick without warning. He hisses at the sudden contact, unable to believe that this is actually happening.
"Jesus, Clarke, you don't have to—"
She lifts her head for long enough to say "but what if I want to?" Then she winks at him—actually winks—before adding, "plus, less mess this way."
He makes a strangled sound. There's no way the girl he's spent two years telling himself he's not allowed to think about is actually sucking his dick in the library. But she wraps one her hands around the base of his cock and his head falls back against the wall, and he can kind of feel the impact. Surely if this was some kind of fantasy he wouldn't feel the pain.
He doesn't quite know what to do with his hands, so he ends up awkwardly putting them on her head. He's worried it's too controlling, but she sighs in what can only be construed as encouragement, so he keeps going, running his fingers through her hair and destroying her braids for good.
Clarke seems to know exactly what she's doing, and it's not long before Bellamy feels himself getting closer and closer to the point of no return. He figures she probably knows what she's doing, considering the wink and the less mess comment, but he's a big believer in open and honest communication, so he manages to articulate "fuck, Clarke, I'm going to come" or something that sounds roughly similar about seven seconds before he actually does.
Clarke, to her credit, was right—there is less mess this way. She lifts her head and grins at him, and Bellamy just flat out stares at her in admiration for a moment before taking her face in his hands and pulling her in for a kiss. "Your turn, princess," he whispers in her ear as he pulls away, and he's called her that before but it's never made her whole body tremble the way it does now.
He reaches down to her underwear, the only item of clothing she's still wearing, and slips his fingers past the waistband, finding her wet and warm and waiting for him. She moans a little when he finds her clit, giving it the lightest flick before pulling his hand away so he can get rid of the underwear. When the underwear is gone, he dives right in, spreading her thighs with his hands and licking at her entrance.
Clarke must have been close when he walked in on her, because it hardly takes him any time to get her whimpering, and he knows that it won't take much to push her over the edge now. He replaces his tongue with a finger and licks her clit instead, dragging his tongue over it slowly. Moments later, she's clenching around his finger, muttering curses under her breath.
They don't bother to get dressed, since no one ever comes to this section of the library. Bellamy finds his hoodie and drapes it over them like a blanket, and they sit against the wall, with his arm around her and their legs tangled together.
"So... do you often ask people who walk in on you to join you?" Bellamy finally asks. He doesn't really think this will clarify the situation, but he has to start somewhere.
"I wouldn't know," she muses, "it's never happened before."