This one is for lllyric! Thanks for the prompt!

The African sun was hot on Clint's back as he made his way through the crowded market. The place was a hot bed of pre-heat pheromones and it was putting him on edge. Phil was right behind him, keeping up with the omega assassin.

The mission was simple, get in, kill the target, get out. But it hit an immediate snag when the African Customs officer had confiscated his heat suppressants. Clint had downed three in the bathroom before handing them over, hoping that the drugs would last for the two day mission. But two days turned into four and soon, Clint was on his sixth day and the target was finally on the move.

Phil had been amazing, massaging Clint's back against his cramps and hustling illegal heat suppressants off of street vendors. Tony had given him some of his prototype pain relief pads to stick to his lower belly. So far, they had been a god send. Clint kept them on for hours and made a mental note to thank Tony when he returned.

The target had just gotten into his black van. Children were crowded around the target, begging for food and sweets, but the man paid the little ones no mind. He glanced around him suspiciously, not noticing Clint and Phil in the sea of people.

"Mobilize, Barton." Phil said, slipping the comm ear piece into Clint's hand. Clint disappeared into a side store, effectively locking the bathroom and setting up his sniper rifle. He slipped back into the crowd with his rifle hidden in his backpack. He climbed the nearest building and got a running start following the target. Phil's voice was calm in his ear as he cleared a five foot gap. the black van wasn't far.

"I got a clear shot, sir." Clint said as he hid behind a parapet on the roof of a doctors office.

"Take it, Agent." Phil confirmed.

The bullet flew threw the air, smashing the window and lodging into the target's left temple. Clint didn't stick around to watch the chaos. He slipped away as quickly as he came. Phil met him back on the street and they blended with the crowd, rushing away. When they finally made it to their shared hotel room, Clint let himself crumble on the bed. He curled around his belly, wincing as strong cramps seized his muscles.

"Are they getting worse, Clint?" Phil asked softly. He laid his hand on the small of Clint's back.

"Yeah. It feels like someone's beating the shit outta me!" Clint whined.

"Do you think we need to stay here for you to ride out your heat?" Phil asked. "To be completely honest, Clint, I don't think I can control myself during full blown heat."

"I just want to go home." Clint whimpered. "I can survive through the plane ride."

"If you're sure." Phil pressed.

Clint nodded against the pain. His stomach felt like it was twisting itself into knots. He was shaking violently against the rush of blood and hormones.

Phil was getting worried. Clint looked absolutely miserable. His brow was shiny with sweat and he was breathing deeply, trembling with each pained gasp. Just how many heats had Clint missed? An omega on mandatory heat suppressants needed to take one heat every six months for detox and release. It was too strenuous on the body for an omega to go without heats.

Clint hadn't had a full heat since he was eighteen.

Phil was rightfully worried, as Clint had wormed his way into Phil's heart. He had made his nest in Phil's head and in his heart, never to leave.

"Phil... I think I made a mistake..." Clint said through clenched jaws.

"Barton?" Phil asked.

"I think I've run out of time. My heat is coming on strong... Phil I need you to... Oh shit!" Clint whined.

They were thankfully boarded in a private room on the plane, just four seats and a door. But it was soundproof and scent proof, and Clint was going into heat.

Phil's cock was rock hard almost immediately. He had been aroused for a while, as they had taken off about two hours prior but the flight took thirteen hours. There was no other way but to bond. A rushed mating wasn't ideal, but sometimes it was necessary to keep all parties involved safe and in this particular case, from ripping their hair out in pained frustration.

Clint was worming his way out of his pants, his scent already sweet and fertile. Most working omegas opted to use birth control to avoid pregnancy. But Clint was allergic.

They shared a heated look, and after Clint gave a consenting nod, Phil moved in. He took control of the situation as well as he could in the confined space. He rearranged Clint's body into a comfortable position, placing his hands flat on the seat and pulling his hips up high.

"Last chance to tell me stop, Clint. If we do this, we're going all the way. There's nothing I want more, Clint, but are you sure you want this?" Phil asked softly.

"please!" Clint panted. "I need you, Phil."

They were naked very quickly. Phil's thick, leaking cock stood at attention between his strong legs. Clint's fluttering slick hole was clenching in anticipation. He whimpered as a fresh flow of slick rolled down his thigh.

Phil took his time drinking in all of Clint. The omega was trembling with the heat, clenching his hole around nothing. His hips were supple, rounding out slightly thanks to the high protein and vitamin diet S.H.I.E.L.D provided for him. He had been drafted at 18, a thin, wiry little thing so malnourished and abused that he flinched when people walked passed his plate.

Phil could remember seeing him suffering around the older agents. The large Alphas were the worst. Clint went out of his way to avoid them. He never looked anyone in the eye and he kept to his rooms. Clint was nicknamed 'the invisible omega' because of how quickly he could disappear. Clint's life in the circus was not very nurturing. He had to hoard food to survive, since there was never enough. His own brother had betrayed him.

Phil had been the one to instigate the new diet. The omega was sickly. Phil had been head over heels for the poor thing almost instantly. He thrived after he had met Natasha, though. Phil was furiously jealous until he saw Natasha lip locking with a beta agent.

Clint whined suddenly, snapping Phil out of his revere. Phil grasped Clint's hips and shoved. His cock slid home in one push. Clint moaned loudly. Phil set a bruising pace, relishing in Clint's gasping moans. Sweat clung to Phil's brow and chest as he thrust into Clint's pliant body. The omega's scent spiked, his hips quivered. Phil draped his body over Clint's. He mouthed around the swollen bonding gland on Clint's neck.

"Do it, Phil." Clint gasped. "I want it, I want you!"

Phil bit hard. The gland broke. Clint screamed and came as Phil's knot tied them together.

"Shit..." Clint panted.

"Wow, that was amazing." Phil murmured, still mouthing the gland.

"I'm glad it was you." Clint was smiling serenely, finally relaxing his head against the wall. "I've had a crush on you since we first met. It was so embarrassing."

"You had a crush on me? I had a crush on you." Phil smiled, rolling to the side, bring Clint down on his lap. "And let's call it an infatuation that gradually evolved into an obsessive admiration that had an element of longing and pining."

"So melodramatic. I like it." Clint smiled.

When they returned to the avengers tower, Tony wouldn't stop teasing Clint. The two omegas spent hours shooting insults between the two of them. Until Tony said the one insult that Clint took as a compliment.

"You're going to get so big and pregnant! You'll be so fat!" Tony taunted.

"You're right. I'll have a baby inside of me, and that baby will be so precious. He'll have me to teach him archery. He'll have Nat to teach him how to interrogate people. He'll have Bruce to teach him anger management and biology. He'll have you to teach him physics and robotics. And Phil will teach him how to shoot a rifle. Fury will teach him how to lead an organization. He'll have Steve to teach him how to lead a contingent." Clint was rambling. "This baby will be the ultimate avenger. Oh my god that's so epic! Tony, you should hurry up and bond with Bruce so that we can have another ultimate avenger. An ultivenger!"

Tony was confused. Clint was happy.

Haha, thanks lllyric! This was fun.

Anyone else have any good ideas for a fic? :)