Stiles straps Laura in her little car seat and watches her suck on her little fist lazily, a little dark wet patch forming on the fabric beneath her chin.

His chest feels tight, warm; he smiles at her and wipes some of her drool from her face with the left corner of his shirt.

Derek taps the steering wheel with his thumbs, clears his throat and asks him, completely out of the blue, "Do you... do you really need me to buy you something for your jeep?"

"Oh my God, Derek," he chokes out, eyes going wide. "I wasn't serious about that. You're not actually gonna be my sugar daddy."

"Really? You don't want to be my kept boy?"

Stiles turns his head to gape at what he can see of Derek's eerily calm face.

And then Derek's jaw muscles tick, and there's this little tilt of a lip that Stiles is intimately acquainted with by now, because this is Derek pushing his buttons back, giving back as good as he gets.

"You asshole."

"I can come home early, if you need me to." Scott looks worried, the weight of his attentive gaze heavy even through Skype.

"Nah, we're fine. Aren't we, Laura?" he asks the infant that's asleep in the rocking cradle Derek had helped him assemble after they'd come back.

"Laura?" Scott asks, and when Stiles looks back to his screen, he is raising both eyebrows and leaning forward onto his arms.

"Yeah." He can feel himself flushing under Scott's scrutinizing gaze.

Scott knows him too well.

"She just looked like a Laura."

"Sure," Scott agrees, earnest, nodding along with his words. And then changes topics to ask him whether they've already gone to Deaton.

Stiles loves him a lot, okay?

Derek comes by a little after Scott hangs up on him to go spend some time with his mom (which had, after all, been the reason they'd taken the trip at all, even though Melissa had been reluctant to take a vacation, and Scott had been reluctant to leave at all), and he's carrying several bags.

Bags of baby stuff. That he brought in through the window.

Stiles resists the urge to mock Derek about this, just grabs Laura from her baby throne and walks up to where Derek is putting all the stuff on his bed.

"Dude? Did you just... go shopping right after we went shopping?"

"These are all things she'll need," Derek defends himself, taking out clothes and diapers and and and out of the bags, putting everything carefully down.

"Sure she will," he replies, mockingly, as Derek takes out a stuffed giraffe out of one of the bags.

"Don't." Derek's cheeks are flushing as he tries to make the giraffe sit down on its own ineffectually. "Cora had one of these when she was a baby."

Stiles grimaces, and is about to offer an awkward apology or something for soiling his childhood memories with his general assholery when he notices Derek's lips jerking almost imperceptibly upwards.

"You are such a dick."

"Takes one to know one."

Stiles huffs.

Laura blinks her eyes open a few times then, tiny mouth parting in a yawn.

Stiles frowns at her. "Don't you dare side with him, little miss."

Derek snorts. Then he turns his back to Stiles, starts rummaging around one of the bags, and says, "it feels right, spending the- spending that money in someone new, in new life."

Then he takes a box out of the bag and puts it on the bed, acts like he hasn't just shaken Stiles' world apart with his raw openness.

When his dad comes back home that night, Derek is still there, casually lounging on his bed, putting batteries in one of the expensive looking baby monitors as Stiles sits next to him, slumped over a little, folding baby clothes, marveling at how tiny socks can be.

"Your dad's home," Derek tells him seconds before Stiles can hear his dad's car parking outside.

Stiles looks at him, at the way he's calmly inspecting the baby monitors' box, mouth in a curl, eyebrows furrowed in focus.

Stiles hears the sound of a car door slamming.

Derek turns one of the baby monitors on.

"So you're just gonna," Stiles gestures at the expanse of Derek's body, "stay there?"

Derek turns to look at him with his lips a little parted. Stiles can see his bunny teeth before Derek licks over his lower lip and says, soft, "Do you... do you want me to go?"

And Stiles opens his mouth to blurt out a well, yeah? But something in Derek's demeanor makes him pause and bite his lips, tap his fingers on the inside of his thighs and sigh out a, "you can stay for dinner if you want?"

Derek's eyes roam around his face, eyes almost vulnerable as he nods.

Stiles, for some reason, nods along with him, biting his lips again.

And that's when Stiles hear the door.

Dinner is excruciating.

His dad doesn't put his gun on the table, and doesn't chew his food threateningly in Derek's directions, because in some bizarre turn of events, it turns out he likes Derek, but everything still feels oddly tense; even though they mostly talk about Laura and where she could've come from, and what it is Stiles' dad can do to try and locate any family she could have, it feels stilted. Like the three of them are walking on egg shells for some extraneous reason.

Derek is weirdly polite, addressing Stiles' dad as sir, and making little small talk questions once they've gone through the topic of Laura.

For some reason, that makes Stiles' gut clench and makes his face feel overheated. His palms feel sweaty, and he's pretty sure Derek can hear his heart beating loudly, and he can't believe he invited this on himself.

"So, Hale," his dad says, after taking a sip of his beer (he'd offered one to Derek too, but Derek had declined, cheeks flushing in a display that had made Stiles hide a smile by taking a sip of Coke), "what are your plans now that things have quieted down?"

Stiles feels the blood drain from his face, and he gapes at his dad, because that is an uncomfortably prying question, Jesus Christ.

"Well, someone has pointed out that my living arrangements may need some work," Derek drops, and Stiles hears his fork clattering as he drops it on his plate to grunt into his hands, "... and I might think they are right, so I guess I'll be on the market looking for a new place."

Stiles peeks from in between his fingers at Derek, and he's treated to the sight of Derek giving his dad one of those creepily charming smiles Stiles has seen him give to other people to get his way. This one seems mellower, though, and that is somehow worse.

"Oh, is that so?" Stiles hears his dad say, and he lowers his hands enough to look at him, and the look he's directing at Derek is one Stiles has never seen on his face: it's somewhere between his sheriff look, the one that screams authority, and his dad look, the one that's stern and soft at the same time.

Stiles has no idea what's going on.

"Yes, sir," Derek replies, and Stiles has to take a sip from his glass to not cringe at the sudden eagerness in Derek's voice.

"And are you looking for a job yet, son?"

Stiles glares at his dad from over his glass because what the hell is even happening, and why is he given Derek the third degree?

"Actually," Derek starts, voice gruff, and Stiles sees from the corner of his eye that he reaches one hand up to rub at the back of his neck, "I'm supposed to be working on my thesis for my masters degree in history?"

Stiles turns to gape at Derek, then.

"That's pretty impressive, son," his dad nods, smiling honestly at him.

"Thanks, sir," Derek replies, flushing to the tips of his ears, looking pleased, and Stiles keeps gaping at him.

"You went to college?" he asks, and as soon as the words are out he cringes because boy, did that sound better and way less rude in his head.

"No need to be so surprised," Derek grunts at him and practically stabs a pea with his fork.

And then his dad glares at him and this is officially the most excruciating dinner he's ever had.

Derek doesn't stay long after they're done eating; he offers to do the dishes, but his dad waves the offer away, clapping his shoulder and extending him an open invitation to come over for dinner whenever he wants to, calling him son again, which makes Derek flush again, and Stiles would feel jealous if it wasn't for the fact that he's well aware that this might be the first time someone has called Derek son in a long time, and that's such a heart breaking thought that Stiles can't begrudge him the way he's soaking the attention up like a sponge.

"Take care, son," his dad tells him, and then he's bidding them both goodnight and leaving them alone in the middle of the living room, with only the baby monitor for company.

Derek doesn't look at Stiles as he puts his jacket on, and Stiles feels like he somehow has to fix this, so he clears his throat, and mutters out a quiet, "Sorry. I didn't mean it like that. Sometimes my brain just," he makes an ample gesture with one of his hands as he rubs his chin with the other, "it just makes me sound like an ass."

"You are an ass," Derek tells him, but when he turns around to face Stiles, he has a smile on his face, and he doesn't seem mad (or hurt), anymore.

Stiles counts it as a victory.

"Takes one to know one?"

Derek snorts.

"Goodnight, Stiles."

He turns to the door, and with his hand on the doorknob, he says, "Give Laura a goodnight kiss from me," soft and gentle, and then he's gone.

And Stiles stands there, staring at the door like an idiot until Laura starts crying.

(That night is better. For the both of them.

Laura doesn't sleep right through it, but she wakes up only two or three times.

Stiles sleeps better, too, though he wakes up a few times unprompted, and just shuffles over to the cradle, puts his hand on Laura's tiny chest, his palm going up and down with the motions of her breathing, and it's... it's calming. It's good for him, it's reassuring.

Not that he'll tell anyone.)