Disclaimer: I do not own The Avengers, Marvel Cinematic Universe, or any of the recognizable characters contained within this story and make no profit from this publishing.

Author's Note: This is my first attempt at Alpha/Omega. As such there are inherent consent issues, as with all stories of this kind. There is no outright non-con. Both parties are enthusiastically participating, only one party has no choice due to biology. If that triggers you or Alpha/Omega isn't your cup of tea this story isn't for you. Also, there is a brief mention of miscarriage. If I continue it will become a bigger topic within the storyline. I have a couple of ideas to continue this. Or I could leave it here. Please let me know if you have an opinion either way. :)

"One's first love is always perfect until one meets one's second love." - Elizabeth Aston

At first he didn't recognize the signs. It had been so long since he'd felt the warmth low in his belly that spread up his chest and down his thighs, the throbbing pain in the small of his back, his skin so sensitive that even the light workout clothes he was wearing felt like sandpaper and only rubbing against things gave him any relief from it without tearing every article off of his body. It had been so long since he could almost literally taste the scents in the air, some repelling, some more attractive than he could describe. It was only when he simultaneously snarled and quite literally bared his teeth while trying to get closer to the hand Tony had pressed to his shoulder that he realized what was going on. It had been so long…so long since his last heat. He hadn't had once since just before he lost his Bucky, his mated Alpha. When he'd come out of the ice to find that he'd lost the only reminder of that mating and hadn't had another heat for nearly two years he figured the trauma of losing his mate and his latest pregnancy, combined with being in the ice for nearly 70 years had killed that part of him. In truth, he'd been relieved to think that he'd never have another heat. Even now, as he felt the earliest pangs of it and finally recognized them for what they were for, it felt a little like a betrayal to Bucky's memory. The fact that the mating mark that Bucky had refreshed the night before he died had completely faded only made it that much harder.

"Jeez, Steve!" Tony shook his hand dramatically though Steve knew his snapping teeth hadn't been anywhere near it, "Just wanted to check on you. You're putting off enough pheromones to knock out a rhino, buddy. I'm going to assume this is your first heat since your time as a capsicle. And what's that about anyway? All of the history books paint you as God's Perfect Alpha and Gift to All Omegas or something. And…"

"Tony," Steve growled. Usually he found Tony's particular brand of verbal vomit entertaining now that he knew the genuinely good man behind it, but the pheromones being released into his bloodstream by his heat addled brain were only serving to put him on edge and he couldn't follow it at all. And that was making him angry. Of course it wouldn't be anything like Bruce's level of anger, but he knew just how much danger he could put people in when he lost control. And that was only making him more frustrated with his current state. He moaned and pulled at the neckline of his relaxed t-shirt even though it wasn't remotely tight.

"Okay, okay…" Tony held up his hands, "History lessons later. After. Whenever. So, you have a plan for your heat, O Captain, my Captain?"

"Don't even think about making a joke about helping me through it, Tony." What he meant to be another growl lost some its potency when it ended on a whine and he had to force his hands to still at his sides, fists clenched, so that he wouldn't tear his clothes from his body.

"I wouldn't joke about something like that, Steve," Tony assured him and for once he even sounded sincere, then he became himself again, "Besides, even if I wanted to offer to help you through, you'd tear me apart once you were deep into it. How did you and…"

"Like fuck am I going to give you details about how Bucky and I spent my heat, Stark," Steve didn't even try to growl, despite his words. It was getting harder to focus on anything; his sight was going in and out. The clothes were becoming a real problem. With another low whine he stumbled from the stool he was sitting on at the bar and forced his vision to clear long enough to make it to the elevator, pushing his way past Tony as gently as he could manage. Tony still stumbled back three steps and almost fell on his ass.

"Jesus Christ, Steve," He exclaimed as he moved to support Steve when he swayed and almost lost his own balance as he waited for the doors to open. Steve pulled away before Tony could touch him, but it made him dizzy to whirl around so fast and he fell against the wall.

"Don't touch me, Tony!" He begged even as his body arched toward the alpha in front of him, "If you touch me…If I get your scent on me…I don't know how…I don't think I'll be able to stop. And you're right…I'd…I'd hurt you."

"Okay, okay," Tony relented and backed away, "But, Jesus, Steve. What are you on? Day one? You can't do this alone. It'll drive you crazy, man."

"You know anyone I wouldn't kill?" The whine in Steve's voice was half sarcastic, half imploring, almost hoping that Tony might actually have the answer like he always acted like he did.

Tony ran a hand though his hair, his scent bleeding distress, as Steve tumbled into the elevator when the door opened, "I don't know. Maybe Xavier has someone who wouldn't mind or something."

"Or something," Steve moaned as the elevator door slid closed. He fell against the wall and fought to keep his hands at his side when all he wanted to do was run them up and down his overheated body. He managed to hold himself together on the short elevator ride until the door finally slid open to reveal his private floor. He stumbled out of the elevator and nearly fell to his knees in his attempt to rip his clothes from his body as quickly as possible. Usually waste made him uncomfortable, a leftover from being raised during the Great Depression, but he was so far gone that he couldn't even care when he realized ripping his clothes from his body meant he literally ripped them from his body. The cloth was nearly shredded by the time he managed to get everything off. He was more grateful than he could say for that silent support JARVIS offered, lighting his path back to his room by illuminating the lights one by one as a simple path for him to follow. His hands were shaking by the time he made it back to his room and the ridiculously large bed that Tony had put in it. He cursed when he realized he didn't even have anything to attempt to see himself through. He'd never thought to have another heat. And now…Not even a knotted dildo to try to fool his body with. The natural lubricant that all omegas produced while aroused was already slicking his entrance. He'd always produced more than enough. He and Buck had never needed any lubricant. Small favors, he thought, as he felt a fresh wave of it from his backside begin to wet his thighs as well.

His breath hitched and he gasped as he threw himself on the bed, swiped all of the pillows and blankets from it and knelt, putting his face close to the warm, neutral scent of clean laundry and his backside high in the air. He'd almost hoped that such a neutral scent would at least calm the fire running in his blood, but it was all to no avail. His hips jerked as a fresh wave of arousal ran from his belly outward, causing a tingling in his fingers and toes and another gush of lubricant between his legs. He sobbed, mostly in frustration, but some in a sorrow too deep to express, as he reached behind himself and plunged two fingers into his entrance, already loosened somewhat just by its own natural processes. He howled at the feel. Not enough. It could never be enough. He felt the tears rolling down his face, the mucus coming up in his chest from his sobs and making his breathing rough. Tony was right. There was no way he was going to be able to make it through this alone. It would break his mind. In some ways it was almost a relief to know. But in others…there was so much more he wanted to do. As much as he missed and mourned his old life, he'd found purpose in this one and it just seemed…wrong…to have it end like this.

His thoughts scattered again and he screamed as he thrust his fingers into himself again and again with all of the considerable strength in his body. Each thrust moved him further and further up the bed until he no longer had space to move and his head hit the wall. He didn't know if it was a minute or an hour of sobbing, thrusting his fingers into himself, and finding no relief before he lifted his head and slammed it against the wall purposefully, desperate to feel something other than his intense need. And when it didn't help he slammed it against the wall again and again until he could feel the blood running down his forehead. He was so lost in the overload of sensation that he didn't even hear the door opening or realize anyone was in the room until a large, gentle hand was between his head and the wall.

"No, Steven. No more of that now," A deep, loving voice said quietly and Steve sobbed again, this time in some semblance of relief, as the hand turned his face from the wall until he was looking up at the alpha whose scent was like lightning in the forest and old leather. He rubbed against the callused and somehow still so gentle hand that cupped his chin as a cool, wet cloth was run over his face, cleaning it of tears and blood and refreshing the overheated skin.

"Thor," Steve whimpered when it all finally hit him that there was an alpha touching him, an alpha in the room with him, and he shot up from his prone position, trying to crawl into Thor's lap. The god had one hip on the bed and had already stripped his shirt, clad only in a well-fitting pair of jeans with the button undone. His long, golden hair was pulled into a loose braid and his electric blue eyes were bright. Steve was certain he had never wanted anything as much as he wanted to scent the gorgeous creature in front of him but the bigger man was gentle and firm in holding him still. He rubbed the back of Steve's neck, up into his hair, down to his scent gland where bonding marks were made until Steve was nearly purring, his body loose and pliant.

"Slowly. Slowly, love," Thor murmured, gentling him back into laying on his back on the bed while he ran his hands and the cool cloth over Steve's body, relaxing him and taking the edge off of his need. Just having an alpha's hands on him was making it better. The need was still there, but it wasn't as urgent. He knew it wouldn't last long. Thor's pheromones would saturate the room soon and he would be just as desperate, just as needy as before, but for now he could breathe. For now he could think.

"Thor…" He said quietly as the alpha before him concentrated on cleaning him. It was something old-fashioned, had already been going out of style when Steve was young, but somehow beautiful. An alpha cleaning and tending to the omega who was going to allow him to share a heat. Tending to Steve, who was going to trust him to do nothing in the throes of that heat that wouldn't allow outside of it when he was too far gone to make a decision. It didn't surprise him that Asgardians still practiced the old ways.

"Thor…" Steve reached out and laid a hand on Thor's arm to get his attention while he was calm and able to think, "What about Jane?"

"The Lady Jane and I ended our romance some time ago," Thor explained as he re-wet the cloth and ran it over Steve's arm, paying attention to each finger when he reached his hand, "After the first bloom of attraction and affection between us faded the lady came to the realization that she has no desire to take a mate, that her work means more to her than a romance ever could. I loved her so. I could not begrudge her that which will make her happiest in this life. In time, I believe we will be friends."

"And you? Do you want a mate?" Steve asked.

"I do," Thor admitted quietly, "I have reached the age at which a man begins to think of a mate, pups."

"Do you…do you want to mate me?" The logical part of Steve's mind knew that it wasn't wise to mate during the first shared heat and didn't know if he ever wanted to take another mate at all, but the omega part of his mind was begging Thor to take him, mate him, and put a litter in his belly.

"Perhaps," Thor's smile crinkled the corners of his eyes fetchingly, "In time. Not this heat, Steven. I have always been drawn to you, from the moment you interrupted my battle with Stark, and if you allow me to court you after our time together is past I would count it an honor. Should we find love in that courting and we arrive at the decision together, only then will I mate you. Do you trust me enough to allow me to see you through your need?"

"Yes," Steve nodded, gasping when Thor finally ran the cloth over his slicked entrance, "Yes." He moaned when Thor did it again, gently, so gently.

"You are stunning, Steven. Do you know just how beautiful I have always found you? As beautiful on the battlefield, covered in mud and blood as you are right now, stripped bare and needing so much. Will you let me give you what you need, dear one?"

"Please," Steve moaned, the cloud of arousal taking over his mind again, "Please."

"You shall have it. You shall have me."

"Thor..." Steve arched his back when Thor gripped his hardened cock and began to stroke him slowly. He panted, breathing in the pheromones that Thor was beginning to release as his own arousal grew.

"A first release to give you some relief before we lose ourselves to the passion, Steven."

"Thor," Steve moaned, nearly coming off the bed when Thor jerked him with a firmer, though no faster, touch and slipped a finger into his body.

"Gently, gently," Thor chided in his soft, low way, "There will be time enough for quickly later. Let this first one come slowly."

"I can't," Steve moaned, his head thrashing against the mattress.

"You can, Steven," Thor encouraged. Steve gasped as Thor leaned over and pressed their mouths together in a sweet, heated kiss, pressing his advantage right away and slipping his tongue in. Steve cupped Thor's face with both of his hands and drank from the beautiful man as surely as Thor drank from him. He cried out against Thor's mouth at the heavy, flowing feel of the pleasure rising in his lower belly, like molten magma. No one had ever been able to gentle him through an orgasm like this in the midst of his heat, not even Bucky. But, Steve supposed, Thor had thousands of years experience. Thor slipped a second finger inside of him and Steve was lost. His back arched off the bed and his mouth opened in a silent scream as his orgasm crashed over him and left him shaking and weak.

His chest heaved as he pulled in great gulps of air and by the time he came back to himself Thor was smiling down at him again, the sun behind his head framing him like a halo. Steve smiled in response to the simple happiness on Thor's face and reached for him. Thor had finally taken off his jeans while Steve was recovering from the orgasm and Steve couldn't help but gasp as the thick, hard evidence of Thor's arousal rubbed against his sensitive backside when Thor allowed himself to be drawn down to the bed and between Steve's legs. They kissed lazily for a moment, Steve not fighting it this time when the heat fog began to take over his mind again. He groaned, half in arousal, half in annoyance when Thor sat up on his knees, pulling Steve up. He situated them so that Steve's legs were wrapped securely around his waist and leaned forward to press his nose to the juncture between Steve's neck and shoulder, taking deep breaths of Steve's unique scent into his lungs, allowing the pheromones and scent to bring him fully to arousal.

"I am not in my rut," Steve heard him say quietly as he leaned forward to scent Thor just as Thor was scenting him, "And I am glad for it. No risk of pups and I will be fully in my mind to take care of you, Steven."

"Alpha…" Steve whined, surprising himself. It had taken years for him to defer to Bucky like that. He chalked it up to it being his first heat in seventy years. He pulled the hairband out of Thor's hair and buried his hands in it, nearly purring, when more of Thor's scent was released and washed over him with the long golden hair that fell over him, like a shield from the world.

"Steven…" Thor held him tighter in his strong arms, "You are such a sweet thing."

Steve made a small noise of happiness from deep in his throat as Thor laid him down again, keeping his legs wrapped firmly around his waist. Steve rubbed his moistened entrance against Thor's hard cock, and pushed back against it, feeling himself fading against his need to have Thor inside him once more. He whined when Thor kissed him again instead of putting his cock in like Steve's body was begging him to do. Thor chuckled against his whining mouth and gripped Steve's hair gently in one strong hand.

"Don't worry, Steven," He said. It was taking everything Steve had to focus on just his few words, the heat becoming too much to think through. He screamed, long and hard, a primal release, when Thor snapped his hips forward and that massive, gorgeous cock was buried to the knot in one smooth thrust. The last thing Steve was aware of was Thor's dark voice and a promise.

"I will give you everything you need."