Mating Instincts

by Nix
(crimsonquills AT gmail DOT com)

AUTHOR'S NOTES: Written for my Steve/Tony Porn Amnesty Day. I hadn't meant to write this one first, and it turned out twice as long as expected. Apparently the supernatural ideas really grab me. *g* Note that this not beta read!

They'd known going in that the virus was extremely contagious. A single bite was enough to instantly transmit a fully active version, complete with transformation during the full moon. A bad mauling was frequently just as effective. It was why the Avengers had sent in Iron Man and Luke Cage. Armor and unbreakable skin had seemed safe.

But the armor was tough, not unbreakable.

Tony sat on the infirmary bed and stared down at the neat white bandages that covered the puncture wounds scattered over his arms while Hank Pym and Doctor Strange stood over him. They were talking, something about getting him out quickly and fighting the infection together, but all Tony could think about was the sound of metal rending under claws, the flash of red, white, and blue, the shield coming between Tony and the werewolf's jaws, the grunt of pain--

"How's Steve?" Tony broke into Hank and Strange's assurances.

They exchanged a glance.

"He was infected," Strange said.

"But only scratched, like you," Hank added quickly.

Strange was still grave, though. "We couldn't work on both of you at the same time. The super-soldier serum gave Steve an advantage in resistance. We stabilized you first. It gave the virus time to establish a stronger hold in Steve than it ultimately did in you."

Tony closed his eyes. "You should have let me wait. You might have been able to clear the infection out of Steve completely."

"Steve insisted," Hank said quietly. "He was frantic, Tony. I think he'd have fought us if we'd tried to take care of him first."

Steve, frantic for him. A part of Tony couldn't help but be warmed by that, and he hated himself for it. He opened his eyes. "So we're both infected. Are we going to change?"

"No," Dr. Strange said firmly. "We stabilized the virus before it became fully active. Unfortunately, we were not able to prevent it from integrating with your body. You will notice...changes."

Tony looked warily from Strange to Hank. "Like what?"

Hank looked uncomfortable. "Increased aggression. Increased speed, strength, and stamina. You might develop a minor healing factor."

"This isn't sounding all that bad so far," Tony said dryly. "Cough it up, Hank."

"You shouldn't dismiss the increased aggression lightly, Tony!" Hank protested. "You can't infect others, but if you get really pissed off in a fight you could end up killing someone. It's going to be a lot harder to hold back, to stop."

"And?" Tony prompted sharply.

Hank sighed. "Werewolves have an incredibly powerful mating instinct." He grimaced and couldn't meet Tony's eyes. "Probably because there are so few of them, and because they've always been hunted. They're driven to find a mate, to claim that mate, and to protect them. When we have trouble with werewolves, it's almost always because we're getting in the way of that somehow."

Tony frowned. "But we're only weakly infected, right? That'll water it down."

"Certainly," Dr. Strange said. "But as Dr. Pym has been attempting to explain, it is an extremely strong instinct; even a weakened version will have a powerful impact on your behavior."

"What I'm trying to tell you," Hank said awkwardly, "is that...Tony, once you find someone you want for your mate, it might not matter to you whether or not they want you back."

Tony stared at him, fighting down a sudden surge of nausea. God, he'd always had a hard time hiding how he reacted to Steve. What if he-- And then Tony had to laugh, the sound taking on a hysterical edge, because Steve had already been stronger than him and if anyone could fight him off it would be Steve, who would be looking for his own mate... The laughter abruptly choked off into a sob.

"Tony?" Hank sounded on the edge of panic himself.

Tony struggled to hold sound inside, unsure if he was going to laugh or cry or scream. He wanted to see Steve, so much, but that was the last thing he should do right now. Maybe the last thing he should do ever again.

"Let me by!"

Tony's head snapped up at the shout from beyond the door to his room in the infirmary. "Was that Steve?"

"Damn it, he said he'd stay put!" Hank snapped.

"We didn't post guards because we believed him," Strange said dryly.

"Guards?" Tony demanded. There was a brief series of thumps from outside the room. Tony felt his mouth curling into a smile, despite everything. "So much for that."

The door slammed open with the splintering sound of a lock breaking. Steve stood framed in the doorway, still in uniform, except for the cowl. His body was practically vibrating with coiled tension, his hands clenched into fists, his expression grim with anger. He fixed his gaze on Tony, who slipped off the infirmary bed to stand without really thinking.

"Steve," Hank said, raising his hands in a calming motion. He and Dr. Strange were standing between Steve and Tony. "You have to calm down."

Tony stared fixedly into Steve's eyes, hardly able to draw a breath.

"Tony," Steve growled, and he was across the room so fast that there was no time for Hank to grow, no time for Dr. Strange to summon more than the first crackle of a spell. Steve shouldered them aside roughly, strength enhanced twice over sending them both sprawling across the floor.

Tony didn't care. Steve was here, right here, his scent--hot and dark and thick with need--filled Tony's awareness. Powerful hands yanked Tony against Steve's body and a snarl escaped Tony before Steve's mouth covered his, open and wet and rough. Tony kissed back fiercely, hands tugging at Steve's uniform, fastenings snapping as he struggled for skin, seams parting.

But all Steve had to do to bare Tony's body was tear the flimsy hospital gown away. His hands roamed over Tony's body, twisting a nipple sharply, squeezing Tony's balls, all but massaging them. Pleasure spiked through Tony, but he forced himself away from the kiss. He didn't have skin under his hands yet, he couldn't claim Steve without skin, needed to take him for himself--

A hard hand clamped down on the back of Tony's neck and pulled him away with nothing but that grip, Steve holding him at arm's length. Tony could feel himself bruising. He whined and reached for Steve, but he couldn't get a grip, was just a hair too far away. All he could do was watch as Steve stripped off his own clothing with his free hand.

Tony panted, short, harsh breaths. He struggled, but a painful squeeze of the hand gripping the back of his neck stilled him. Steve was stronger than him. Steve was stronger...Steve was strongest...Steve was...was... Steve turned Tony and bent him over the hospital bed, held him down with the hand on his neck, kicked his legs wide, and pressed against him from behind. Steve's body, heavy with muscle, covered Tony completely. Tony bucked up hard, but he didn't move Steve an inch. Steve was stronger. Steve was pack leader.

Steve let go of his neck, pinning Tony with his weight, and wrapped one hand around each of Tony's wrists, forcing them down onto the infirmary bed. "Mine," Steve growled into Tony's ear.

Tony whined and went limp in acknowledgement, spreading his thighs wider. Steve pressed tighter against him, the hard length of his cock grinding against Tony's ass. His skin was searingly hot, the mating need burning inside him.

"My mate," Steve's voice was deep and fierce. He shifted his hips, nudging the head of his cock against Tony's hole. He slick only with pre-come, hadn't worked Tony open gradually, but that was good, that was right, the pack leader was strongest, took what was theirs. Steve forced Tony's body open for him and Tony panted and bit at the sheets of the bed and squirmed beneath Steve's weight, once he was sure the movement wouldn't dislodge Steve. Growling, Steve thrust deeper, roughly, and Tony struggled harder, making Steve hold him tighter, pin him harder, make him work for it, make him take Tony.

Instead of shifting to a more secure grip, Steve leaned into Tony harder, using his body to hold him down, and let go of his wrists and moved his hands to Tony's cock and balls instead, massaging the sack, jerking on Tony's cock, driving wails of helpless pleasure from him. Steve wrung Tony's orgasm from him, milking his cock for every drop of come while Tony whimpered and shook.

Hands still wet with Tony's come, Steve held onto Tony's shoulders and set about fucking him in earnest, grunting with effort each time he buried himself in Tony. Clinging to the infirmary bed, Tony just moaned, his body pliant, taking the driving of Steve's cock with exhausted ease. Steve finished with a triumphant shout, pouring himself inside of Tony, hips grinding close.

Slowly their bodies cooled and rationality began to creep back in. Tony's body ached fiercely, his ass protesting its abuse, still distended by Steve's cock. But when Steve carefully pulled away, the whimper Tony clamped down on was of protest, not pain. Tony had a moment to dread Steve's inevitable apology before Steve helped him straighten up and turn.

But there was no apology in Steve's eyes when Tony managed to meet his gaze, only a deep satisfaction. Steve reached up to cup Tony's face in one hand. "You're my mate now," he said firmly.

Tony couldn't stop himself from saying it: "I always was."

Steve smiled and drew Tony into an embrace. "Yes. I could smell it. I could smell you, even out in the hallway. I knew you were here and that you were mine and...I had to get to you." He faltered. "I had to."

Tony hugged him. "It's okay," he said softly. "We've got each other now. We can figure the rest out."