The sun had moved noticeably across the sky by the time Peter and Tony woke up from their nap. Tony's easy smile allowed Peter to relax back against him, once more ignoring his nagging conscience that said sleeping with your boss in his office during work hours was a fireable offense.

Still naked, Tony made his way to an ornate bar and began pouring himself a drink. "Want anything?" he offered.

Peter almost asked if they should be drinking during work hours, but in for a penny, in for a pound. "Get me something light. A gin and tonic, maybe, but go easy on the gin."

"With lime?"

"Sure."

As Tony mixed their drinks, he stared at Peter, thinking deeply about something. He handed Peter his drink before he said, "For the life of me, I can't remember the reason you came into my office in the first place. Did you say something about the arc reactor?"

Peter nodded, taking a small sip of his gin and tonic and making a firm resolution that that was as much as he would drink. "Yeah, I think I figured it out. Howard Stark's notes suggested that the arc reactor would only work with a heavy element, going so far as to insist that the element hadn't even been discovered yet. Well, there have been over a dozen elements synthesized or discovered since Howard Stark's time, yet we're still no closer to finishing the arc reactor. And if you run the numbers, a heavy element would never work. Just imagine the cost overhead if you have to synthesize an element every time you wanted to install an arc reactor in a new city. It's just not feasible."

Tony sank back onto the couch beside Peter and swirled the ice in his glass. "It's sweet that you'd bring this doom and gloom directly to me, but you really—"

"I'm not done," Peter cut him off. "There is an answer, and it's an incredibly simple one. Everyone was so convinced Howard Stark was correct that no one ever considered the possibility that he was wrong." He glanced at Tony, having forgotten temporarily that Howard was Tony's father. "Sorry. I didn't mean to imply—"

Tony waved his hand to cut him off. "If I could have moved forward the arc reactor project simply by letting the world's top scientists know that Howard Stark wasn't infallible, I would have done so from the very beginning."

Despite his earlier resolve, Peter took another sip of his drink. His body was beginning to flush once more, both from the liquor and from being in such close proximity to Tony. His cock began to stir hopefully, but Peter was determined to discuss his hypothesis about the arc reactor.

"So what if we went the other way? What if we started at the beginning of the periodic table?"

"Hydrogen?"

"Hydrogen."

Tony was silent for several moments. He continued to swirl the ice in his glass, staring unfocussed across the room. Finally, he said, "What do you think, J?"

Peter jumped when an accented voice spoke seemingly from all around them. "It's never been tested before, sir. It would be worth running the scenarios at minimum." As the voice spoke, Peter whipped his head around, trying to locate a monitor, speaker, or camera.

"What—?"

"Peter, meet JARVIS, my AI."

Slack jawed, Peter stared at Tony in awe. "He's incredible!"

"Thank you, Mr. Parker."

A thought crossed his mind, and he blushed and leaned close to Tony to whisper, "Was he listening the whole time while we—?"

"Nah, the Booty Call Protocol kicks in. The room goes on lockdown, and J discreetly goes offline."

Without thinking, Peter teased, "A whole protocol for hooking up in your office? How many times have you used that?"

"A lot."

An awkward silence followed, Peter's thoughts churning. He had read articles and heard rumors of Tony's playboy past; what did he gain by throwing that dirty laundry between them? Besides, what did exes bear on a current relationship? And were they even in a relationship? Weren't they just…

Fooling around?

Without realizing it, Peter had drained his glass. Tony took it and sauntered back to the bar. Peter didn't protest as he started mixing a refill.

"Simulation complete."

JARVIS' voice filling the room caused Peter to jump again.

Tony abandoned the bar and pulled on his DITA sunglasses. "Talk to me, J."

"Using hydrogen in the arc reactor has produced a stable reaction in 96% of simulations run."

Tony looked like he was reading something behind his sunglasses, his eyes flitting back and forth across the lenses. "It's worth a try, at the very least. Have the parts ordered to my lab." Without further preamble, Tony started getting dressed. Peter didn't realize he had gotten fully hard watching Tony pull expensive fabrics over his skin until Tony turned toward Peter and smirked salaciously. "Like what you see, baby boy?"

Mouth agape, Peter nodded, his eyes riveted to where Tony was buttoning his dress shirt sleeves.

Chuckling, Tony gathered Peter's suit and brought it to him on the couch. "As much as I'd love to go round two, I think it's time I brought you home."

Peter stared in awe for a solid minute before he was able to take a second step into the lab. A large robot rolled over to him and let out several beeps and whistles before zipping back across the lab. Tony watched Peter bemusedly as he took him on the tour, introducing Dum-E and U and explaining several of his projects. Peter soaked in everything wide-eyed, his brain running at a hundred miles an hour and trying to speak even faster.

Tony recognized the familiar ache in his chest as he watched Peter look like a kid on Christmas morning. Always one to fall too hard too fast, he had almost let the "L" word slip earlier. They hadn't even discussed how they were defining their relationship, and here he was, ready to propose.

What if Peter didn't want anything more than casual sex?

"That's why you need to discuss the relationship like actual adults," Pepper had told him nearly a hundred times.

Far too often, though, Tony had ended up with his heart broken in a million pieces. He never did things by halves, and time and again he had proved too much for the other party and had lost them before they'd even begun. He supposed that's why he avoided the "relationship" conversation…

But Peter was different, and he deserved more from Tony.

Finally, Tony steered Peter toward the materials for the arc reactor. Peter fell into building with Tony with ease. The lab had always been Tony's personal, intimate space, and he wasn't sure how he'd feel sharing it with someone else. But it was like Peter had been born for this role, so naturally assisting and directing Tony as if he's been by his side for years.

Time became a blur, the two of them lost, elbows deep, in building the arc reactor. Eventually JARVIS ordered a pizza for them, but neither Peter nor Tony were willing to take a break long enough to do more than take an occasional bite.

And then Tony was laying in the final pieces of the first prototype. They stood way back as Dum-E and U powered it on, and when it didn't explode right away, they cheered and whooped. Safety protocols had been preprogrammed to power it down after thirty seconds, and just as the blue glow faded away, they felt their own energy slowly drain. Yawning, Tony directed Peter to the shower where they quickly washed up before collapsing onto Tony's bed.

When they awoke, Tony was still giddy over the success of the first arc reactor prototype. He hurried Peter through a quick breakfast of scrambled eggs and toast, taking only a black coffee for himself. He bounced eagerly on the balls of his feet before hurrying Peter back into the lab.

The second prototype had as much success as the first. Peter and Tony took notes on different configuration updates before attempting further tries. Tony leaned back in his chair, his joints popping as he stretched.

At some point, Tony must have given Peter a T-shirt and a pair of sweats to change into, but it was all a blur. He grinned lecherously as he let his eyes rove over Peter.

"Fuck, you look good wearing my clothes."

Peter caught Tony's gaze and returned his expression. "I think I look best not wearing any clothes at all."

"I have to confess I've had a recurring fantasy where you fuck me in the lab."

Peter climbed in Tony's lap and slung his arms around his neck. Kissing him, he said, "I like that I'm in your dreams."

Kissing back, Tony suggested, "Want to make my fantasy come true?"

Peter's eyes lit excitedly. "I don't know what's got me harder: the thought of being inside you or the fact that we've essentially solved the world's clean energy problem in your basement."

"That's an easy one for me."

"Yeah?"

"Obviously the arc reactor."

"Oh, ha, ha. You know, maybe I won't—unh—"

Tony had slipped his hand down the front of Peter's sweats and gave a long, slow stroke. He sucked hard on Peter's already bruised neck before using his tongue to soothe the tender skin. "You were saying?" he teased.

Peter turned his head so Tony had better access to his neck and thrust his hips more purposefully into Tony's hand. "I don't remember," he mumbled. "Something about you letting me ride you in this chair." When Tony removed his hand from his pants, he whined. "Come back," he begged.

He met Peter's eyes and said firmly, "My fantasy is for you to fuck me, not the other way around."

A low moan escaped Peter's throat, and his eyes grew hazy with lust. "Oh, Tony… I can…"

A deep kiss. Peter's hands clutching at Tony's shirt. Tony's breath catching in his throat. Tongues clashing. Fingers tangling in silky hair.

Peter slowly worked his way to confessing, "I've never fucked anyone before."

Tony pulled back, concerned. "Oh, shit, I didn't take your virginity in my office, did I?"

"No, absolutely not. I've had sex before. I've just never been…you know. The fucker. I've always been the fuckee."

Once again, Tony made a promise to himself to discuss Peter's previous relationships.

But for the time being, he was determined to get that pink cock deep inside him.

"I'll walk you through it. Or I can always prep myself."

"No, I think I'd like to…" He blushed shyly before whispering in Tony's ear, "I want to finger my daddy."

"Fuck."

Tony pushed Peter off his lap and, thrusting aside blueprints and diagrams, directed him onto the workbench. Without bothering to remove the sweatpants, Tony mouthed along the outline of Peter's cock. "You're so good to me, baby. Can't wait to get this inside me."

Peter hesitated. "Really?"

"Really, really. Your cock is so perfect." His hands rubbed against Peter's sweatpants as he continued to talk, occasionally pausing to run his lips and tongue along the fabric as well. "It fits just right in my mouth; it's going to feel incredible in my ass. Mmm… Can't believe I get to be your first. I just want to take care of you, baby boy, treat you like the king you are. Fuck, I'm so hard thinking about you pounding my ass. When you're getting close, I want you to pull out and cum on my puffy hole. Would you do that for daddy?"

"Nnh…"

Tony worked the sweatpants down Peter's hips, guiding him off the workbench momentarily so he could pull them all the way off. He took Peter into his mouth, letting saliva build so he could work up and down more easily. He moaned as he blew Peter, already on the verge of being incomparably blissed out.

Peter threaded his fingers through Tony's hair and tugged, earning a deep groan. He lay back on his elbows and forearms so he could move his hips in time with Tony's mouth.

Pulling back, Tony frowned.

"What's wrong?" Peter asked.

"I don't have any lube in the workshop. And somehow I don't think synthetic oil should be used inside the human body." He placed a kiss on the tip of Peter's dick, a bead of precum sticking to his lips and pulling away in a long string. "Sit tight, beautiful. I'll be right back."

While Peter waited for Tony to return, he finished removing his clothes. They had been in the workshop for who knows how long since breakfast, so he also took time to clean up as best he could in the bathroom. Tony must have done the same because when he returned with the lube, his hair was damp.

Tossing Peter the lube, Tony grinned devilishly. "I can't fucking wait for this, beautiful. I've been dreaming about your cock since that first night we met. Fuck, those pants you were wearing… Do you still have those?"

"Yeah."

"Shit, babe, you need to wear those again sometime. Sit in my lap and let me jerk off to how fucking gorgeous you are, then let me cum on them."

Peter had softened while waiting for Tony to return, but his words had him fully hard once more. He dropped to his knees and took Tony's cock in his mouth. Tony leaned contentedly against the workbench and watched Peter's mouth work up and down.

Peter popped open the cap on the lube and poured some in his hand. He knew what he liked when he fingered himself, so this shouldn't be any different, right?

Right.

He hesitated at the entrance, looking up at Tony for permission, unable to say anything with his mouth still full of cock. Tony smiled down at him and assured, "Go ahead, beautiful. If you do something I don't like, I'll let you know."

Tracing the outer ring felt just like when Peter did it to himself. With a gentle push, he was further in, his finger being squeezed from all around. He sucked harder the farther in his finger went until Tony reminded him to relax.

"You're doing just fine, gorgeous. Now just go in and out with that…mmm, yes, just like that. Hey, ease up on sucking my cock, okay? I don't want to cum too soon. You can add a second finger, babe. Want me to turn around?"

After Tony turned around, Peter found himself face to face with his glorious hole. He had a sudden urge to kiss it, so he did. Tony tensed up, moaning, gripping the edge of the workbench. Peter did it again, just to watch Tony struggle to keep his balance.

The lube was flavored, which confused Peter's tongue momentarily. He ran the flat of his tongue against his hole, remembering how Tony's beard had felt against his skin when he had done this to him. He toyed with the idea of growing a beard before diving more voraciously back into Tony.

"Fuck, Peter, that's good… That's—oh…"

Peter put his finger back in; this time it slid in easily and deeply.

"Fuck, baby, get a second one in there."

Putting in a second finger had Peter nervous he was going to hurt Tony, but those fears were soothed by Tony's moans of encouragement. Knowing what he himself liked, Peter crooked his fingers, going deeper, recognizing immediately when he found Tony's prostate by his high pitched cry.

"Feel good, daddy?"

"Nnh…"

Peter liked the idea of rendering Tony Stark speechless, so he prodded his prostate once more.

"Peter…!"

He thrust his fingers in and out, transfixed by watching it happen. Tony had collapsed onto the workbench, arching backwards to meet those fingers more pointedly. His head rested on the edge of the table as he babbled incoherently.

Peter assumed he must be doing something right, and as his confidence grew, the more bold he became. He scissored his fingers, stroked his walls, and pushed more deeply inside.

"Peter, baby, I need to take a break. Otherwise, I'm going to cum all over the floor."

"I did good, daddy?"

Tony gathered Peter in his arms and kissed him on the temple. "You did so good, baby. Just let me breathe and calm down. Shit. Get yourself lubed up, beautiful, and I'll…" He draped himself back over the workbench, his legs spread and his ass out. "Ready?"

Peter lined himself up and held his breath. He'd had previous boyfriends who had pushed in too swiftly, so he pledged he would go slow for Tony, especially since he wasn't convinced he'd done adequate prep. He pushed forward, but the head of his cock slipped past its intended target. He lined himself up again.

"Relax, baby doll. I can feel your tension from here. If you need a break, or if you've changed your mind—"

"I haven't changed my mind. You're—" He bit his tongue as his true feelings threatened to spill forth. They still hadn't discussed if they were anything more to each other than fuck buddies, and he didn't want to scare Tony away. "Just—"

Tony looked back over his shoulder. "Sorry, Peter, I didn't mean to—oh… A little lower, and you've—ah!"

The head of Peter's cock was inside, and he waited for Tony to give a signal that he was ready to continue. Peter watched Tony's hand clench and unclench before he nodded. "Keep going, baby boy. Fuck, I can't believe you're really—uhn… Ah, wait a second… Mmm… Alright, go ahead, beautiful."

Peter bottomed out and groaned deeply. It really was hard not to pull out and thrust forward with everything he had. Breathing deeply, he said, "Tell me when you're ready."

"I'm ready," Tony said almost immediately. "Fuck, Peter, I've been ready for this for so long. You're everything—" He broke off with a moan as Peter found a rhythm.

Peter realized his eyes were closed, so he forced them open to take in the glorious man beneath him. They had got caught up in each other and had forgotten to disengage the second arc reactor prototype. A blue glow bathed the lab, casting cerulean color across Tony's back. His muscles tensed and relaxed as he thrust backward against Peter's movements, his moans providing harmony to Dum-E and U's occasional whistles and chirps.

Tony shifted his hips purposefully until Peter was hitting his prostate in just the right way. He collapsed from his forearms onto his chest, practically screaming in pleasure.

Peter ran his hands down Tony's sides, feeling his muscles and smooth skin. Part of his brain was convinced this wasn't real, that he'd wake up hard and wanting, cock weeping with desire.

"Fuck, Tony, you're so tight… This is…"

Tony shifted again, and Peter found he was able to thrust more deeply. Holding onto his hips, he built up a quicker pace, losing himself in the sound of skin meeting skin.

"So good, Peter…"

"Tony…"

The workbench rattled beneath them as Tony drove back to meet Peter's thrusts. He never allowed anyone in his workshop, so the idea of Peter taking him on the workbench right after they'd spent days working on the arc reactor prototypes had him frantically writhing beneath his baby boy. And the fact that Peter had never fucked anyone before had him aching in a way he hadn't expected it would.

Unable to hold back much longer, Tony took himself in hand, stroking himself erratically. "Fuck, Peter, so good—"

"You gonna cum soon, daddy?"

"Yeah, getting close—"

Tony keened as Peter shifted again, hitting his prostate from a different angle. His walls clamped unbearably tight around Peter, his own cock drooling in excitement. With an incredible amount of willpower, Tony took his hand off his cock and gripped the edge of the workbench.

"Want to come on your cock, beautiful."

"Tony—"

"I've wanted to come on your cock—for so long—"

"—yes—"

"You're—"

"I—"

"Fuck! Peter!"

Tony came in spurts, white trails marking the floor. He fell against the wood surface, feeling high as Peter continued to pound into him through his orgasm. His head rolled to the side, a broad smile across his face.

Eventually Peter pulled out in deference to Tony's oversensitivity and jacked himself to completion. Remembering Tony's earlier wish, he aimed at his hole, though in his euphoria, he only made a half-hearted effort.

Tony looked over his shoulder and met his gaze. "Daddy has a favor to ask of you." His voice was still husky, his eyes lust-darkened, as if he hadn't just come on Peter's cock.

Peter smiled easily under Tony's brown eyes and let his hand run down his side, his thumb catching in spend and smearing it down his hip. "Anything for you, Tony."

"Could you…" He hesitated, and Peter realized he had never seen Tony Stark hesitate for even one second. Almost shyly, he continued, "Could you push your semen into my hole?"

A jolt of lightning flashed through Peter's body, and his cock made every effort to rise again. With a groan, he sank to his knees behind Tony and used his tongue to push his own cum into Tony's used hole.

Angled as he was, he watched Tony's leg muscles tense in pleasure as he rocked up onto the balls of his feet. Peter placed a tender kiss first on his entrance then on each cheek before sitting back on his heels and looking admiringly up at Tony.

"Anything for you," he reiterated.