*A/N: I do not own Supernatural or any of the characters. This is basically just some Sastiel smut. I'll probably write more. Reviews are appreciated. If there's anything you want to see, suggestions are welcome.

Sam could feel the cold wind blowing through his jacket. The night before, Cas had left a message saying that they needed to meet, without Dean and that Dean couldn't know. Sam thought it was weird, but Cas had always been a little strange. When he got to the place Cas had wanted to meet, no one was there.

"Sam, I'm glad you came," Sam's back was facing Cas when he spoke. Cas looked anxious, and Sam just wanted to know why.

"Yeah, of course," Sam assured him. "Why did you want me to meet you here? And why without Dean? Surely anything you say to me can be said to him."

"Well... I..." Cas stammered. He took a deep breath and restarted. "This doesn't have anything to do with Dean. I wanted to meet you here because I wanted to tell you..." Cas looked down at the ground. "I wanted to tell you that I think I'm falling in love with you," he mumbled.

Sam didn't know what to say. He definitely didn't think that this was the reason why Cas wanted to meet him privately. He wasn't sure what to say or how to respond. Yes, there had been times when he'd fantasized about Cas, but he also knew that his brother had feelings for the angel. Looking at Cas now, he couldn't care less about Dean's feelings. Sam found himself pressing his lips against the smaller man's and Cas wasted no time kissing him back.

Cas wrapped his arms around Sam's waist, pulling their bodies closer together. His hands wandered down to the hunter's tight ass, moving it so their hips rubbed against each other's. "I have a vehicle here," he whispered while lightly kissing Sam's neck, "if you want to move this someplace else." Sam nodded breathlessly and Cas led the way. They ended up at a van with the backseats taken out. Before Sam could even ask, Cas sheepishly said, "I was hoping this would happen."

They climbed into the back of the van and Sam instantly started to remove layers of the angel's clothing. Sam unbuttoned Cas' white shirt, leaving kisses where each button was. Sam could see that Cas was getting more and more aroused the lower he got. Sam undid Cas' pants and pulled them off, along with his underwear. Sam wrapped his lips around Cas' hardening cock, eliciting a small moan from the angel.

Cas had his hands on the back of Sam's head, forcing the hunter's mouth further down on his cock. Sam groaned when the tip of the angel's dick hit the back of his throat. Sam pulled his mouth off of Cas' cock with a pop and began kissing back up the angel's torso. He gave Cas a heated kiss on the lips before starting to take off his own clothes. Cas wrapped his hand around Sam's already-hard cock and began to stroke it gently before lowering his lips onto it.

Cas licked along the hunter's shaft, making sure that he paid attention to every part of Sam's cock. Cas could feel that Sam was getting close. All of his muscles were tensing up, his back was arched, and his moans were getting louder. "Please... Cas..." Sam muttered between moans, "I need... you... inside me." Cas grabbed the bottle of lube and squeezed a generous amount into his hand. He rubbed his hands together and coated his cock before massaging the lube into Sam's tight ass.

"Please..." Sam whined when Cas had three fingers inside. "Now." The angel obliged and lined his cock up with Sam's hole before starting to gently push himself inside. Sam let out a low groan and Cas pushed his entire cock into Sam. "Fuck, yes..." Sam growled. "C'mon Cas, fuck me."

That was all the invitation Cas needed. He began to pump his hips back and forth. He loved hearing Sam's moans and the way the hunter cursed. Cas leaned over and began gently kissing and sucking on Sam's neck. Sam tilted his head back so that Cas had better access.

Sam couldn't believe what was happening. He had fantasized about being fucked by Cas many times, but he never thought it would actually happen. And yet, here they were. Cas on top of him, kissing his neck, fucking him. It was better than any fantasy Sam may have had. With every thrust of Cas' hips, Sam was closer and closer to the edge. He didn't want it to be over though. They were both almost there.

Sam couldn't hold it any longer, "Oh, fuck... Cas," He moaned as he came, his ass tightening around Cas' cock. The sight of Sam coming undone was enough to send Cas over the edge as well. Sam felt Cas' warm come shoot into his ass.

Cas fell on top of Sam, panting. They both lay there, trying to catch their breath. Sam's phone started ringing from the pocket of his jeans. "Hello?" Sam answered, still trying to catch his breath.

"Sammy?" It was Dean. "Where are you? And why are you so out of breath?"

"I told you, I was going for a walk," Sam replied. It's Dean, he mouthed to Cas.

"Well, get back here as soon as possible. I have a case for us," Dean said before hanging up the phone.

"Dean found a case, so I should get back to the bunker..." Sam told Cas.

Cas nodded in agreement. "Just... don't tell him about this, okay?"

"Don't worry, I won't," Sam winked. "But maybe we can do something like this again after Dean and I get back..."

"I'll keep in touch," Cas smiled. Sam quickly pulled his clothes back on. Before he got out of the van he planted a firm, passionate kiss onto the angel's mouth.

"I'll see you soon," Sam closed the door. As he walked back to the bunker, he was still in shock. After all the times he fantasized and dreamed about Cas, it finally came true. Sam didn't care if his brother had a thing for Cas, the angel had chosen him.