Work Text:
Derek presses the doorbell to the new Stilinski-McCall home, balancing the bowl of homemade potato salad in his arm. He can hear laughter and shouting, but there isn’t anyone coming to the door; after a moment of staring, Cora just rolls her eyes and pushes it open. They walk slowly through the empty house, Derek holding his potato salad in front of him like a shield.
"We’re all in the back, son!" Derek hears the Sheriff call warmly, and Derek walks into the backyard.
"Oh, thank you, Derek, I’ll just take that," Melissa says, taking the potato salad and setting it on a nearby table. She’s wearing a maroon swimsuit and flicking water gently from her hair; the Sheriff is in plaid swim trunks turning burgers on the grill, Erica is sitting by the poolside, wearing a polka-dot bikini and giggling as Boyd spreads sunscreen on her back. Lydia is sunning herself on a nearby chair as Allison braids her hair, Kira and Isaac are in the midst of what looks like an epic pool-noodle battle and Stiles is dunking Scott below water.
Scott surfaces, laughing uproariously and splashes water at Stiles. He catches sight of Derek standing awkwardly by the table and shouts, “Derek! You made it! Didn’t I tell you it was gonna be a pool party, dude?”
"Er, no," Derek says, shifting slightly in his jeans and t-shirt, tearing his eyes away from the water sluicing down Stiles’ neck. "You said it was a housewarming barbeque, so…"
There are a few cries of “aw, come on” and “Derek, you gotta join us!” from various members of the pack before Derek just throws his hands up and says “It’s fine, guys, really…”
Cora’s already peeled out of her shirt to reveal a bright blue swimsuit underneath. “What? I thought it was obvious it was a pool party!” she grins brightly at him, and promptly cannonballs herself into the pool, splashing water everywhere, including all over Derek’s jeans.
Scott pulls himself out of the pool. “You can totally borrow one of my mine, it’s totally cool,” he says, dragging Derek back into the house, up the stairs and into his bedroom. Scott rummages around in a chest of drawers and then tosses a scrap of something at him. It’s colorful and lurid, and what is it supposed to be, a handkerchief?
"What is this?" Derek glares at Scott, stretching the thing out.
"It’s a speedo, dude," Scott says. "It’s all I’ve got right now, unless you want me to go through Stiles’ stuff. I don’t even think he’s unpacked yet."
Derek tenses. “It’s fine,” he says quickly, staring at the stars-and-stripes patterned speedo in his hands.
Scott smiles and leaves the room, and Derek blinks at the offending piece of fabric for a few moments before giving in. He did tell Cora he was going to try to be more social, after all. He tugs off his clothes and pulls on the thing, and it’s snug.
Derek feels a little self-conscious when he steps back out into the backyard, and everyone whoops and hollers for a moment, and Erica whistles loudly, but then everyone seems to get over it quickly and Derek actually has a good time. They play volleyball in the pool and eat burgers from the grill and laugh at Isaac when he falls off his pool-noodle throne and throw themselves into the deep end of the pool far too many times and eat more burgers and hot dogs and potato salad than they can stomach.
It’s a lazy, happy afternoon, and Cora is nudging Derek slightly, as if to say See? That wasn’t so hard. Derek just pushes her into the pool, laughing as she splutters and complains that she just dried off.
The only thing strange about the afternoon is that Stiles seems to be avoiding him; he made a beeline for the other team when they were picking sides for volleyball, and he jumped up in surprise and promptly fled when Derek tapped him on the shoulder and offered him the ketchup earlier.
Derek tries not to think about it too much when he heads back into the house to grab some more sodas from the fridge. Maybe Stiles caught him staring earlier and was creeped out?
Derek has a can of orange soda for Cora and root beer for himself in his hands when he hears it; Stiles talking loudly in the hallway, Scott chuckling.
"—can’t believe you would do this to me, Scott! This is like, the ultimate bro betrayal—and since we’re actual brothers now—I am doubly betrayed!"
"Dude, your face when he walked out—"
"Not funny, Scott! You know how ha—difficult it was to watch Derek wear that ass-hugging flag all afternoon?”
Scott is snickering, and Derek can feel his face go hot as Stiles continues. “I was this close to just telling him I wanted to pledge allegiance to his flag, and to the general public of his round ass, because I am one horny nation that wants to be under—”
Stiles and Scott walk into the kitchen and Derek coughs and grips the sodas a little tighter. “Er. I was just—soda. Yeah, I just—” Derek walks past them, fighting down the blush on his face.
"Oh shit," Derek hears Stiles say before he exits the house.
"What took so long, Derbear?" Cora asks as Derek hands her the soda.
"Nothing," Derek says.
Cora narrows her eyes at him. “Yup, totally nothing, that’s why your face is redder than the stripes on your butt, big brother.”
"I said it’s nothing," Derek insists. "I’m gonna head out early, I’ll see you at home."
His clothes are still in Scott’s bedroom, so Derek heads back there; the swimsuit is plenty dry as he’s been out of the water for the past hour, too, so that’s nice, Derek doesn’t hang to bring a wet swimsuit home before he washes it and returns it to Scott.
Derek is taking off the speedo when the door creaks open and Stiles walks in. “Hey, Derek, Scott told me you were in here, and I just wanted to apolo…” Stiles freezes mid-sentence and Derek can feel Stiles’ gaze hot on his bare ass for a moment while he fumbles for his boxers and pulls them on quickly.
"Apologize! I wanted to apologize," Stiles squeaks, his face flushing pink.
Derek pulls on his jeans and then looks up at Stiles. “So you didn’t mean it?”
"Yeah, I mean, no, wait, what?" Stiles blinks, confused.
"Did you mean everything you said—about wanting to be under—" Derek waves his hands awkwardly. He’s no good at this, should he even—and Stiles is just standing there, wide-eyed and silent, until words start spilling out of his mouth.
"I mean, I do think you’re hella fine but then I usually try to keep that to myself and I don’t really think it’s a secret that I have a huge crush on you but then Scott totally tried to get me to embarrass myself by getting you to wear that speedo and it totally worked because you heard me—"
"Stiles! Stiles, shut up," Derek is saying, but Stiles is still babbling pointlessly, words running over themselves, hands gesturing wildly, so Derek just steps forward into his space and shakes him slightly until Stiles stops talking. "Stiles, I did not know about your crush or anything like that until today," Derek says.
"Oh," Stiles breathes, and Derek can practically feel the heat radiating off his body, that’s how close they’re standing.
"I was trying to tell you that I like you too but you just kept talking—mmf!"
Stiles’ eyes light up and he leans in to kiss Derek, a quick press of lips and then he leans back, blinking nervously. “Sorry, I just thought—was that okay?”
Derek’s brain catches up with whats happening after a few seconds and he smiles back at Stiles, who relaxes. “Yeah, I was just surprised.”
Stiles raises his eyebrow. “What, you think we’re going too fast?”
Derek smirks at him. “Well, you’ve already seen my butt, so,” and Stiles laughs and kisses him again.
This time, Derek kisses back enthusiastically, that is until Scott opens the door and groans, “My room, guys, really?”