What about Buck ending up having a threesomes with various 911 couples??
I assume this is a 5 AU facts thing?? But it would have to largely be fictional couples, because his sister is in one of the main couples and another main couple is two lesbians. BUT....
1. New to LA Evan (not Buck yet) meets a pretty woman at a bar and starts flirting and there's a connection, but she says she has a boyfriend. He jokes that he can join them, and she gets this look on her face and texts someone. And fifteen minutes later, she says, "Come over." And he meets her boyfriend and worries the guy will kill him, but the guy mostly just sits against the headboard and watches Evan fuck his girlfriend while he jerks off and makes really intense eye contact that Evan is having a hard time looking away from. And when Abby is in the bathroom cleaning up, Evan gets the feeling that the guy wants to kiss him and slowly, carefully crawls toward him, and the guy (Tommy? Johnny?) looks like he's having a full internal battle before he grabs Evan and kisses him like his life depends on it. And Evan scrambles to climb into his lap, and he's hard again and a lot of things are clicking into place for him very quickly about guys he's known. And Tommy or Johnny or whatever breaks the kiss and looks like he's in pain as he tells Evan he should probably go.
2. Buck has a threesome with Eddie and Shannon after Eddie drunkenly reveals that he and Shannon have both only really ever been with each other. At that point, he's pretty sure that's all that either of them will ever have, because they're working things out. So when Buck offers to at least give Shannon a chance with someone else, Eddie rolls his eyes but then comes back two days later and is twitchy and nervous as he says, "Yeah, uh, so she's...interested. In that. With you." And Buck asks if Eddie wants to be there, and Eddie shrugs and says sure why not. So they have a tipsy, giggly threesome that's mostly just Eddie and Buck taking turns with Shannon. She begs them to kiss, and they do, and Buck says, "See? Dudes aren't so bad." And Eddie grins and says, "Yeah, you're a good kisser. But I'm not sucking your dick." And Buck, who fully threw himself into every app after that first threesome, says, "That's fine. Do you want me to suck yours?" And Eddie's eyes get huge, and Buck doesn't get him all the way there, Shannon ends up riding him instead, but Eddie's almost embarrassed by how much he likes it. "A mouth's a mouth," Buck says, shrugging. "Don't worry about it."
3. So this one's an almost, but Buck finds out Athena's ex-husband is gay and he's at dinner at her and Bobby's place one night. And he's asking her if there were signs, and she says there were some. He asks if they ever had a threesome with a guy, because he's pretty sure he was the third person in a situation like that once. "Dude," Bobby says, popping his head out of the kitchen. "Seriously?" And Athena rolls her eyes and says it's fine. "What, you think I didn't have any fun before Michael? Or after him, for that matter? It was always a woman and a man, though." Buck considers the question he's about to ask for a while before he offers, and she laughs so hard he thinks she might hurt herself. Bobby sets the chicken down and asks what's so funny, and she waves at Buck to tell him. He mumbles out his question again, and Bobby says, "I'm way too old for this conversation. Eat your dinner." And Buck grins and asks, "So if you were, like, five or ten years younger it'd be a yes?" And Bobby sighs at the ceiling.
4. Connor and Kameron come to him and ask him about the sperm donation thing, and Buck is flabbergasted but honored. When they try to figure out how they'll do it, Buck jokingly offers to just do it the old-fashioned way, and Connor tells him to shut up. "What? No, I wouldn't do that to you. I meant the three of us," Buck says, because he saw Connor naked a lot when they lived together, and Connor's ass is a work of art. "Oh," Connor says, blinking. "I mean..." "If we're about to be parents..." Kameron adds consideringly. "But if it doesn't work, we'll use the clinic. This'll be cheaper anyway." So they meet up after a few false starts, and the only problem is that Connor absolutely is really into this. He's actually had Kameron peg him a few times, and he's been thinking he might have maybe invited Buck to live with him for less than noble reasons. Buck isn't weirded out, because it can be hard figuring out you're bisexual. The only real problem is that Connor has a breeding kink, just not where Kameron's concerned. So Buck ends up fucking Connor, who's very vocal about said breeding kink, and when he cums inside him, they kind of all look at each other and start laughing after. "I don't think that one's gonna take," Kameron says between giggles. Buck does get hard again and fucks her, but it doesn't take, so they go through the clinic instead.
5. It's Tommy again, except it's Tommy and his new boyfriend, a guy named Mark who's a little older than Buck and hot and nice enough. And Buck makes a joke about hoping this threesome goes better than their last one, because they'd made that connection eventually (Buck was pretty drunk at the time, so was Tommy, and they'd kept the lights low). They're very intentional about keeping Mark included, but it's too easy for them to get wrapped up in each other. Buck can ride Tommy and forget anything else exists right up until there's a guy pressed against his back and kissing his neck and waiting his turn. When Mark goes to the bathroom, Buck doesn't hesitate before climbing on Tommy's lap and kissing him, whimpering when Tommy grabs him tight. "Please," Buck begs, not even knowing what he's begging for. And Tommy grabs the lube and slicks himself up and Buck rides him again, no condom this time. Tommy won't stop kissing him and whispering sweet, filthy things to him, and he lifts Buck and lays him on his back and drives into him until Buck is whining his name and pulsing cum over Tommy's fingers. And Tommy presses his forehead to Buck's chest and shudders through his orgasm, Buck carding his fingers through his hair. "Stay," Buck begs, because they're at his house. "I can't," Tommy says, kissing his jaw. "I want to, but I can't." And he gets up and finds Mark in Buck's living room waiting to leave. "So you guys have some stuff to figure out," Mark says, putting on his jacket. "Best of luck." It's been three months, nowhere near as intense as Buck and Tommy's first three months. They've always used condoms, so Mark seeing Buck ride Tommy without one was a pretty solid indicator that Tommy is less over his ex than he'd previously stated. So Tommy walks back into the bedroom, lays down, and says, "Alright, so my ride just left. So I've got time to talk." By morning, they're emotionally wrung out and cuddled up together under the covers, and Tommy asks him if that's the first threesome Buck's had since their other one. "Not even close," Buck mumbles. "There's been a few." Because he had a lot with strangers and near strangers for a while there, and he and Natalia had one with her ex-roommate once. "They're fun, but I like this more," Buck says, threading their fingers together. "Unless you want to have another one." "Not a chance in hell," Tommy says, laughing.
