Dean was resting beside Castiel when he suddenly began to feel weird. His body felt hot and he began to sweat. He turned over, trying to get comfortable but he was so fucking horny he couldn't take it. He whimpered quietly, alerting Cas to him.

"Dean, what is wrong?" Cas sat up in alarm, looking down on him. He was now soaked in sweat and felt as if he were in a sauna. He sat up as well, peeling his shirt off of him.

"Cas, fuck me." He growled, advancing swiftly on the angel. He smashed their lips together in a frantic and needy kiss, taking the older man by surprise. Cas disappeared, reappearing several feet away.

"Though I do not oppose to such an action, your sudden urgency alarms me." Cas said calmly, face red with lust. Dean tore off his clothes, fabric scattering everywhere, and turned around on his hands and knees, exposing his ass to his partner.

"Take me, Cas. Please, Castiel!" Dean was on fire, erection firm against his belly. He heard Castiel groan behind him and smirked. Dean didn't use Cas's full name often, but when he did Cas found it extremely sexy. He felt Cas behind him, grabbing his ass roughly, trying to keep himself contained. "Give in to me, my love." He whispered seductively and he felt Cas's grip tighten.

"D-dean, something is c-clearly wrong with you." His voice was a whimper and it made Dean's dick twitch. He spread his legs further, offering his hole to his mate. Castiel dove his head in, giving Dean's opening a firm lick.

Dean moaned, pushing himself closer to Cas. The angel pulled back quickly, attempting to regain control once more. "Dean, something is not right."

-

"Yeah, you're not inside me." Dean growled, making Cas groan again. Castiel backed up until he was against the wall, eyeing his submissive partner. He closed his eyes, hoping to be able to think more clearly. Understanding hit him.

"Dean! I know what is wrong!" He pulled out his phone, ignoring the whimpers coming from the demon.

"Sam, we are experiencing a problem... No, no. Please do not come here." He glanced over at Dean. "I believe now that your brother has a part of my grace inside of him, he is experiencing the time that humans refer to as "heat". It is something angels go through for one week out of the year, starting after mating."

"Wait, angels have heat? Ew. Can he get... pregnant?" Sam questioned on the other side of the phone.

"I am not certain. I do not believe two males have ever mated before, at least not while one is experiencing heat." Castiel threw another worried glance at Dean, who was now fingering himself on the bed. Cas looked down, lust filling him.

"So.. what do we do?" Sam asked awkwardly.

"I suppose all I can do is keep him away from anyone for this week and handle him myself."

"Ew. Again. Okay, I'm gonna go.. anywhere else. Call me when this thing is over." Sam hung up and Castiel threw his phone into the nearby chair, turning towards his mate with primal need.

"My little submissive mate, acting like a little whore for me, I see." He growled out, making Dean whimper. "You like when I stare at you, all exposed for me, don't you?" Dean nodded frantically, head lowered.

Castiel leaned over Dean, putting his mouth right to the demon's ear. "You're my little bitch."

-

Dean whimpered loudly at this, digging his fingernails into the bed. A small part of him thought how normally, he would likely be irritated at being so submissive, but it was overridden by the extreme urge to please his dominant mate and to be relieved as well.

"P-please." He whined out, entire body shaking and dripping with sweat.

"You're so fucking sexy, you little slut." Cas grinned, pressing his finger to Dean's hole. "So wet and tight, all for me." Cas slid his finger in, stroking Dean's inner walls and making the demon mewl.

Cas prepped Dean quickly, and Dean could feel the urgency in his mate. Soon, the angel was lining himself up, entering his partner smoothly and thrusting in hard. Dean yelped out, cumming onto the bed. He was shocked by how quickly he had came, hot spurts hitting the dark sheets in streaks.

"So eager, I see." Castiel mused, slamming into Dean again. Dean moaned loudly, still feeling his orgasm as Cas hit his prostate over and over. He felt himself grow hard again and groaned, reaching down to rub himself.

"No. You're going to cum untouched like the horny little bitch you are." Dean whimpered, bringing his hand back up.

"Y-yes sir." He gasped out, cumming again only a couple minutes later. He began to think that being in heat was actually pretty fucking fantastic.

This process continued several more times until Cas finally thrust into Dean as hard as he could, emptying himself into his mate's ass. He collapsed on top of him, kissing his sweaty back.

"Again?" Dean asked, breathing heavily.

This was going to be a very long week.

-

One week of sex-filled escapades later, Dean was starting to feel much better. His body cooled down, and he began to feel rather sore.

"Ugh, what the fuck." He groaned, cuddling up to a satisfied-looking Castiel.

"I tried to let you know. But you insisted upon showing me your lovely submissive side." Cas grinned down at him, receiving a playful scowl from Dean.

"You didn't think to warn me about the whole thing?" He grumbled.

"I didn't know; you are a demon. I did not realize that it would affect you in the way an angel is effected. Also we are both of the male gender."

"Yeah, I guess. Fuck, that was insane though."

"Most definitely." They exchanged smirks.

"I feel weird." Dean said suddenly, frowning.

"What do you mean?" Cas sat up, holding Dean's hand.

"My stomach hurts like fuck." Dean groaned, curling up into a ball.

"Perhaps it was all the copulating?" Cas offered, running his hand down Dean's back soothingly.

Dean sat up, sprinting to the bathroom suddenly. He vomited into the toilet, lurching forward.

Cas panicked, rushing in and patting Dean on the back. "Dean, what's happening? What do I do?!" Dean realized that Cas had probably never seen a person vomit, and was likely extremely scared.

"I..I'm fine." He choked out in between puking. He heaved again until there was nothing left and sat back, a large frown on his face. "I think I might be sick."

Castiel was hyperventilating, eyes wide. "Hey, relax." Dean went on to explain what vomiting was in the best way he could, comforting Cas.

"Is it possible for you to get sick?"

"I don't think so. I'm just as confused as you are. Is this a weird side effect of being in heat?"

"No.. unless.." Castiel's eyes widened even more and he trailed off.

"Unless what?" Cas didn't move. He didn't even blink. "Unless what, Castiel?!" Dean was beginning to get a little scared now.

"We need to go to the store." Cas said. Before he was finished speaking, they were standing in front of a convenience store. Cas rushed in, finding the correct aisle and grabbing something that Dean hadn't seen.

"What is that?" Dean asked, jogging to catch up. Cas walked up to the counter, throwing money onto the table. The young teenager checked out the item, which the angel was still hiding from Dean. He walked out, dragging Dean with him before transporting them back to the hotel bathroom.

"Pee on this." Castiel shoved something into his hand. Dean looked down at it finally.

"A pregnancy test? You've gotta be fucking kidding me."

"Dean, angel pregnancies are much shorter than human pregnancies. It would not be uncommon for you to be experiencing morning sickness at this time."

Dean frowned and unwrapped the test, making Cas leave to pee on it.

"There. Now we wait." He said sarcastically, setting the test down. Cas paced nervously, making Dean snort. "I'm a dude. Chill out."

"I can not 'chill out', Dean! I may be a father. And so may you."

"This is friggin ridiculous Cas." Dean said. He picked up the test. "See? Negative, just like it should be." He pushed the test into Cas's face, who turned pale.

"Dean..." Cas breathed out, looking at the test, eyes wide with shock.

"What?... Oh." He said, looking at the test. There were two pink lines.

"I'm pregnant."