A/N: THE END, because chapter fics are too much responsibility and I need to remember to keep to shorter endeavors when I have two jobs and an original story going. :-) But I've really enjoyed writing this one. You've all been awesome readers and commenters, and made this even better.

Enjoy! And you can rest assured I'll be back with something in the near future.

Derek sat on Stiles' bed, having neatly folded up the stretched-to-destruction clothing he had borrowed, along with his own larger underwear that he hadn't gotten around to replacing, and set them on the floor. Stiles found himself unfairly preoccupied with how Derek was wearing his underwear as he moved to sit across from Derek in his desk chair.

"So...does it feel like all of that happened over the last few days, or...seven years ago?"

"...both? It's...hard to explain." Derek's brow scrunched in that familiar sourwolf way, and yet his eyes held the endearing eagerness and affection that Stiles had started to get used from the younger Derek.

The thought of actually having this awesome Derek-combo—so damn hot, and a comic book geek to boot—all for him was a little more than Stiles could fully grasp with a sane mind. He had barely been able to handle having younger Derek.

So, hopelessly awkward and afraid that any of the next few words out of his mouth might sabotage how well this was going, Stiles forced out a laugh and said, "I can't believe what a big liar you are, being totally into me all this time and acting like you hated me."

Derek frowned, though his raised eyebrow proved his amusement. "I wasn't acting like I...hated you."

Stiles raised an eyebrow back at him.

"I was…trying to keep you from liking me. If you hated me...maybe it would be easier not to…think about you."

"Because...you don't deserve to be happy?" Stiles said with offhanded sarcasm.

"Because..." But Derek's eyes glazed over, betraying how that was exactly what he had been thinking. He sagged forward, letting his arms rest on his thighs, and stared at the carpet. "Damn it. I just...I just…" he closed his eyes, "…I wish it had been you," he said again, like he had said in the jeep, only so softly, Stiles almost would have needed wolf ears to hear it.

Carefully, even though he could never be silent or stealthy enough for Derek not to hear every move he made, Stiles slid from the desk chair to the floor, and settled on his knees in front of Derek. He placed his hands on Derek's knees, waiting for hazel to flick up at him.

Stiles grinned when they did. "You know, in a way…it kinda was me. What do you remember now when you think back to being sixteen?"

"You," Derek said steadily, his eyes clear and focused on Stiles' face. "Before her. Like a dream."

"It was real…" Stiles answered quietly. He held Derek's gaze for maybe an eternity too long, then stood up to move to the bed and sit beside Derek instead. Their arms touched, and the inherent warmth from Derek made Stiles' breath hitch. "So…you still want to borrow Marvel Zombies?"

Derek gave a short laugh. "Actually…I already own all of it, but it has been a while since I read through some of it."

Stiles turned to stare at Derek, amazed that his previous guess that Derek had a secret stash of comics at the den was actually true.

Derek looked at him sideways, still slumped forward. "After…the fire," he began, "Laura…almost every week, started…trying to replace the comics I'd lost. We always had plenty of money, but we still tried to be frugal about most things. Even so, she always gave me extra for comics, or picked some up for me. It was silly and small and…made all the difference in the world." He smiled somberly, eyes going distant for a moment as he remembered his sister, who had managed to survive and be there for him…only to die what was still a handful of months ago.

There was something still so surreal about being able to know and comfort this…werewolf who had once seemed so untouchable, and Stiles allowed himself to revel in how he was one of the very elite few who actually knew Derek Hale.

He slid his hand onto Derek's knee again. "I know…it can't be exactly like it was," he said. "You're him, but you're...you, too. It's not the same, because you're not the same. And I'm okay with that. I love learning new things about you…remember?" Stiles grinned as he moved his hand slowly from Derek's knee…toward the hem of his shirt and slipped his fingers up underneath to Derek's firm stomach beneath.

Derek sucked in air from the tickle of Stiles' fingers, catching his wrist instinctively, but smiled back at him—that perfect, crooked-canine smile.

"But I won't lie and say I don't appreciate the things that are the same," Stiles grinned.

He pulled his hand away, and Derek allowed it, watching intently as Stiles shifted onto one knee and lifted the other leg over, settling himself in Derek's lap. Stiles thought he might slide off from the precarious position, but Derek's large hands came up to hold Stiles in place around his lower back.

"For instance…I don't see any reason why we can't…still…" Stiles grinned wider rather than finish the thought, and while Derek looked skeptical for a moment, like some small part of him wanted to resist as his older self had for so many months, his eyes quickly softened, and he leaned up toward Stiles' lips.

Knock. Knock.

"You alright in there, kiddo?" came the Sheriff's voice from the other side of Stiles' door.

"Okay…maybe there's one reason…" Stiles whispered. Then the actual feeling of panic crept in and he dove off of Derek's lap and up the bed.

Bless Derek for not having to be told to hide, because he immediately dropped over the side of the bed where he was hidden between the bed and the window. Stiles had just settled himself back seemingly nonchalant against his pillow when his dad opened the door.

"Uhh…yeah, Dad, I'm fine," Stiles called. "Just…taking it easy while trying not to actually fall asleep. Harder than it looks. I've been...going over topic ideas for my next Econ paper."

His dad came over to the side of the bed, wearing his usual concerned expression, though infused with sympathy rather than the accusatory look Stiles usually earned. "Maybe you'll try writing about something actually related to Economics this time," he said with a humored raised eyebrow.

"I was thinking of a paper on the devastating effect the vast amount of billionaire superheroes would have on the economy if they actually existed. That's relevant," Stiles grinned. He actually had been considering that topic.

His dad chuckled and shook his head. "Just promise you'll only ever use your super-intelligence for good."

"Deal."

"Ready for dinner?"

"Uhh…" Stiles used all of his self-control not to glance to the side where Derek was hiding on the floor. "I think I need a little more resting time. Maybe…an hour or so? Then I'll be able to scarf something down. I swear." Stiles half-expected to hear Derek snort at that and give himself away. There was silence from the side of the bed, but he imagined Derek grinning anyway.

What? Stiles wasn't above subterfuge for sex.

The Sheriff nodded. "Well, if you're sure, I'll keep it on simmer. Tell me the second you feel worse, if you do."

"Absolutely."

The Sheriff took a moment to reach over and pet Stiles' head—since it wasn't actually possible to tousle his short hair—then headed back out of the room and closed the door behind him.

Stiles let out a deep breath. Yeah, he was going to hold off explaining Derek to his dad for as long as possible.

"So…who has the worst effect on the economy by hoarding all their wealth for superhero gear? Tony?" Derek's voice filtered up from the floor.

Stiles rolled over to the side of the bed and peered down at him, taking in the relaxed way Derek was just lying there, hands folded neatly over his stomach as he looked up at Stiles with a smooth, carefree expression that Stiles wanted to keep there forever. That Derek was on a first-name basis with said superheroes made a strange warmth build in Stiles' belly.

"According to Forbes Fictional 15…definitely Tony," Stiles said, "though Bruce isn't far behind. Or am I not allowed to cross universes?"

Derek just laughed. Laughed.

Stiles slinked off the bed onto the floor…and right on top of Derek where he snuggled in like the pack member he had apparently been since day one. "I could write about wolf pack relationship dynamics instead. Isaac totally thinks you're his mom."

"Don't be silly. You're the mom." Derek's tone was playful—juvenile even—but his large, warms hands on Stiles' waist were…all grown up.

Stiles sat up slightly so that he was basically sitting on Derek's hips, legs straddling the Alpha beneath him. Derek's hazel eyes stared fondly up at him, urging Stiles to do…whatever he wanted to do, without even having to speak.

Sure, they could wait, and take things slow, take their time, now that things were back to normal. But damn it, Stiles wanted—needed—the affirmation that what had happened between them before really was…real. He believed Derek's words and the way Derek looked at him, but he needed to feel the absolution.

So he started by feeling the toned muscles of Derek's abs again as he slid his hands up underneath Derek's black T-shirt. Again, Derek sucked in air at the slight tickle, but Stiles also saw how his pupils started to dilate.

"You're...really not going to freak out or…give me some lame speech about how I'm too young and we should wait?" Stiles prompted softly, even while he continued to slide his left hand up Derek's chest, and his right began unbuttoning Derek's jeans—which he had put on only a few minutes prior.

Derek looked thoughtful but not at all like he wanted to tell Stiles to stop now. "I should…for a number of reasons," he said. "You are young. Your father won't approve no matter how you explain this. It's all moving so fast, and…maybe you're too young to really understand what 'mate' means…"

Stiles paused at the sight of his own Batman underwear staring back at him, and how Derek's voice had trailed. He looked up into hazel again. "I understand what it means. I do. I'm…it for you. If you want the fairytale ending instead of just casual sex your whole life—not that that isn't without merit—I'm it. Which is…this insanely huge responsibility, and I'm sure at some point I'll feel overwhelmed by it…at least a little. But you know what I'm not going to do?"

Derek looked back at him expectantly.

"I'm never going to wish we didn't give this a chance. Coz, crazy as it is to me…I like you. You're this awesomely layered person, who's part geek, part supernatural creature, part Greek god, and you're destined to be with…me. I think I can put up with the occasional sourwolf moment for that. And if you get on my nerves too much, I can always still key the Camaro."

Derek snorted, but Stiles was through with the witty banter for now. He slid his hand inside the opening of the Batman boxer briefs and found Derek—so warm and already half hard.

Stiles' breath stuttered a little as he stared into adult Derek's face. "I can't believe I'm touching you…" he said, like he had said last night, only…he was even more amazed than he had been then, because this…this was Derek.

Adult Derek wasn't as immediately vocal as the younger version had been when Stiles began to gently tug within the confines of cotton, but once Derek was fully hard and Stiles had to slide the jeans down Derek's hips to free him fully, the coolness of the air made Derek gasp. Then Stiles' hand was back, having pulled Derek out through the opening in the shorts rather than take them off completely.

"You know…you can totally keep these," Stiles said, indicating the too-tight underwear. He was never completely done with the witty banter.

"Maybe we can share…" Derek said with a slight smirk—an expression that younger Derek never quite got across the same way and that made Stiles melt.

The thought of wearing the underwear after Derek had been wearing them—well, he'd wash them first, coz otherwise that would be kinda gross—made Stiles' cock jump. He had been thankful for his jeans when his dad came in, if only to hide his own partial erection at the time, but now he wanted to be free.

Stiles had a plan—sort of. He knew what he wanted, at least. So he released Derek long enough to slide his own jeans off, leaving on his underwear for now, and then carefully removed Derek from the opening in the Batman underwear and pulled them down his legs, so that the shorts and jeans had Derek's legs locked together where they gathered at his knees.

Stiles hunkered lower on top of Derek's body, and began to lower his head between Derek's legs. He kept his eyes on Derek's face the entire time as he took him into his mouth.

Derek gasped with a little more force this time, and struggled not to arch his hips.

There was something so dirty about the whole thing, because Stiles' dad was home and right downstairs, and Derek was so much older than him and wearing his Batman underwear around his knees, and they were on the floor of Stiles' bedroom, hidden from the door, and…and Stiles was sucking Derek off with an eager mouth.

Stiles played those details over in his mind again and again, and suddenly really wanted to touch himself. Or have Derek touch him. He reached down and gave himself a firm squeeze just to keep his wits about him, but continued to lick at the precum and salt on Derek's cock, relaxing his throat as best he could as he sucked Derek in.

Finally, the mules and moans Stiles had so appreciated from the younger Derek began forming in older Derek's throat, his head tossed back to display the long line of his neck as he held himself up on his elbows. Then he snapped his head forward to look at Stiles—to watch—and his eyes flickered Alpha red.

"Stiles…" Derek said, and fuck, the gruffness of his voice was like sex personified.

Stiles pulled his lips away, then ran his tongue slowly across them, watching as Derek watched him. The strength in Derek was something that had been easy to forget when he was sixteen and shorter than Stiles, but when Derek grabbed Stiles by the front of his shirt and pulled them both up into a harsh, frenzied kiss, while simultaneously reaching down between Stiles' legs and gripping him firm…Stiles was abruptly reminded of just how encompassing adult Derek really was. And he really freaking liked it.

A slow moan built in Stiles as Derek pulled him from his boxers and spread his skin with precum, pumping firm with practiced fingers and…fuck—Stiles definitely had that word on the brain. He finally turned his mouth away from Derek's insistent, probing tongue to take a breath and release his moan at the same time.

Derek's words came hot against his ear. "I want you inside me again."

Stiles' brain promptly shut down. "Huh…wha…?"

"Stiles."

"O-Okay, I…may need you to repeat that...several times."

Derek gave Stiles' cock a gentle squeeze, held Stiles close with his other arm, and ran his tongue along the contours of Stiles' ear, before repeating, "I want you…inside me again. I want…to remember that feeling. Then…next time…" Derek pulled back so he could look Stiles in the eyes. He grinned promisingly.

That sounded like a fantastic idea, said Stiles brain—or his libido. They were pretty well mingled at this point. So Stiles gave what may have been a vague nod and swept back in to capture Derek's lips. Derek's hand slid away, and they settled more comfortably on the floor so that Stiles was in Derek's lap, their mutually wet, hard cocks grinding together between them as they kissed.

Stiles hissed when he tore his lips away again. "Back…on the bed?" he gasped, though they had begun a steady rocking motion that was so going to push him over the edge any second if they didn't stop.

Derek didn't answer with words. He held Stiles around the hips and just…stood up, like it was no feat at all to lift all of Stiles' and his own weight—which it probably wasn't. Derek carefully dropped Stiles onto the bed, kicked away his shorts and jeans, tossed his shirt off over his head, and then he was just…naked…walking around the bed to the drawer with the warming oil.

Stiles still had his boxers around his thighs, and a T-shirt and thin hoodie on. He kept his eyes glued to the glorious form of naked Derek while kicking and tossing his own clothing away as quickly as he could.

For a moment, Stiles considered how he had felt when he was with the younger Derek, like…maybe he wasn't such a scrawny, skinny kid. Older Derek was…broader, taller, just…holy shit, where did he find all those muscles? But it didn't intimidate Stiles as he had once feared, as he devoured every curve and line of Derek's body, the Alpha just standing there beside the bed with the little bottle of oil in his hands.

He smirked at Stiles. "What?"

"You are aware of how hot you are, right?"

Derek just smiled wider and climbed onto the bed, purposely trailing his eyes over every inch of Stiles to show his own appreciation, which made Stiles blush and feel like the color was probably spreading all the way to his toes.

But hey, just because Derek was Derek again didn't mean Stiles had to turn into some blushing bride. Especially considering what Derek had asked of him. So Stiles reached out to take the bottle of oil and slid over to the side of the bed, indicating for Derek to lie down. When Derek started to position himself onto his stomach, Stiles shook his head.

"I want to see your face this time," Stiles said.

Derek complied, lying on his back instead. "However you want me."

Stiles shuddered. He didn't have the stamina for a second more of foreplay—or Derek's sex-roughened voice—not when Derek was spread out before him like a banquet. Stiles positioned himself in between Derek legs and went straight to work. It was surreal to be so reminded of the night before…while at the same time amazed that this time he was with the Derek he had assumed would kill him for this. But Derek—adult and gorgeous and totally strong enough to rip Stiles' arms off if he wanted—spread his legs and sighed in pleasure with every careful stretch of Stiles' fingers inside of him.

Reservations and apprehensions quickly fell away, faster than they had the first time, because now Stiles knew what he was in for; he knew Derek wanted him, at any age, and Derek had asked…asked for this.

As Stiles finally began to push in, amazed that Derek still felt just as tight, and hot, and fuck…suddenly Stiles was overwhelmed even more by whatever crazy mate connection they had built the night before. It was as if Stiles could feel his own pleasure…and Derek's too, mixed together and echoing back at him.

Stiles moaned a little too loudly as he thrust forward, and Derek smiled even as he reached up to cover Stiles' mouth. Stiles took that action as a challenge, much as he was thankful that Derek was conscientious of being in the Sheriff's house, and sucked one of Derek's fingers into his mouth. It was Derek's turn to moan, though he managed a bit better at keeping the sound muffled.

There was a brief moment where it really did overwhelm Stiles, the realization that he was fucking Derek Hale, in his own bed, and it wasn't a dream or a fantasy, or some crazy happenstance because of a meddling witch. And sure, it was freaking awesome how smooth and warm and just perfect it all felt, and how insanely hot Derek looked with his finger in Stiles' mouth while he reached down to give himself a few needed pulls...

But more than that…was that this wasn't just sex. It was awesome sex, but it was…more. This was an honest-to-God, supernatural, fated connection.

"I love you," Stiles gasped, surprised even as he said it, even though he'd already implied it and practically said it earlier, but to actually just say it was something that had to happen as the realization of that emotion surged through him.

He really loved Derek. He really did.

Derek pulled himself up, even though it looked like it folded his body uncomfortably and broke their steady rhythm, and kissed Stiles. "I love you," he said back.

Stiles shuddered as he released, suddenly, but with such a glorious crescendo. Quickly replacing the hand Derek had been using on himself with his own, Stiles pumped swift and tight until Derek released too, with a moan that he stifled behind his own hand as he let himself fall back onto the bed.

For a moment, Stiles wondered if he'd just...wake up now, and it would be young Derek there, or no Derek at all, but the scenery didn't fade.

Slowly, Stiles dropped down next to Derek, scrunched in tight on the small bed, side by side. Their breathing filled the room. Eventually, Stiles lifted up onto his elbows to look at Derek, down the full length of him, sweaty and sticky and...seriously, fuck.

Derek brought Stiles' attention to his eyes with a gentle, coaxing hand on his chin. "I can't promise...that everything will be like it was. But I can promise...that you're mine. And you'll always be mine. I'm not going to be easy to walk away from now." Derek looked a little haunted as he said that, just slightly, hidden behind his eyes where Stiles could just barely make out the pain, the remnants of fear that Stiles might actually walk away some day.

"You'll be sick of me within a week...and you still won't be able to get rid of me," Stiles said with a grin.

Derek just laughed...and nodded.

They kissed, and Stiles tried not to think about his dad, or the rest of the pack, or how things had changed, or how things still would change. Right now, he was content. Right now...he was Derek's Hale's other half, his mate, the final missing piece to putting the sourwolf back together, and that was something Stiles was honestly proud of.

"Can I still call you Youngblood?" he whispered against Derek's lips.

"Urg, I hate that comic." Derek instinctively rolled his eyes, just like younger Derek had done that first night. Then he smiled.

Stiles squeezed Derek tightly, letting their bodies mold against each other as they laid together on the bed, and grinned back at him. "I know."

Outside the Stillinski house, an unseen pair remained in shadow, not watching the events within, per se, but knowing full well the importance of what had happened.

"See, I told you Derek might surprise us."

"You did."

"And you were content to just sit back and...watch."

Deaton smiled at the woman beside him. "Well, we are Watchers."

Morell quirked a corner of her mouth upward. "Times change. They need to be ready, and Derek was going to drive his pack into the ground without a true anchor to hold onto."

"You may be right," Deaton nodded. "I'm not complaining."

They stood in silence for a moment, watching the house with a sense of calm satisfaction.

"So...I was on vacation?"

"Unless you want to tell them the truth."

"I suppose there was no other way to avoid them coming to me for help. You do make an interesting redhead."

"Strawberry blonde," Morell corrected. "You could stand to flex your powers once in a while."

Deaton chuckled lightly. "Oh...I wouldn't want to give too much away. But...thanks...for this. I think it might actually be just what they need."

"They...the pack, or they, Derek and Mr. Stillinski in there?"

Deaton merely smiled wider, and turned to take off down the street and leave the pair inside the Stillinski house to their privacy. "Oh, let's just say...all of the above."

THE END

Morell was going to be the witch before I even posted chapter one, so glad to finally get that in there. :-) Hope you all enjoyed how this ended! Let me know!