After leaving the diner, Dean was still erect in his jeans. Cas had had his foot all in the hunter's business while he was trying to eat. Luckily, though, Dean could moan and pass it off as his reaction to the burger.
Dean pulled into a gas station because Sam was whining about having to pee. "That's what you get for drinking so much damn coffee!" Dean said as Sam got out of the impala. Almost immediately after the door shuts, Cas is on top of Dean, straddling him, pressing his lips to the hunter's. Dean's eyes go wide at first before he kisses back. It takes him a second before he realizes something and has to lightly push Cas off of him. "Cas, baby, Sam could come back any second." Dean panted out, looking into Castiel's dilated, blue eyes. "Whenever he comes back I can maneuver to the backseat within a millisecond, Dean. Your secret of being a homosexual is safe." the angel replied before smashing his lips back into Dean's.
Dean grunted and grabbed the back of Cas's head, intertwining his fingers with his hair. Castiel dug his hips down into the hunter's causing them both to let out a slight moan as both of their dicks got harder. Cas pulled away from Dean's mouth and quickly placed his lips on the hunter's jawline, kissing down his neck and continuing to grind their hips together.
"God, Cas, I want you so bad right now." Dean said, throwing his head back. Cas smiled and bit Dean's neck, eliciting some nice noises from the back of his throat. Cas began to suck and kiss and bite the same spot over and over again. He liked to leave his mark on Dean, let people know he was taken. Dean was, in fact, his after all.
Dean grabbed Cas off his neck and pulled him to his face to kiss him again, hard. The angel shoved his tongue into Dean's mouth, who lightly bit back. Dean then made his way down to Cas's ass with his hands. He gripped it with both hands, pulling Castiel's hips down onto his own while squeezing his cheeks. Cas pulled away, breathily stating, "D-dean... If you don't stop I will not be able to control my sexual desires and your brother will see me pleasuring you orally and I will NOT for ANY REASON stop until you've reached climax." The elder Winchester looked into his angel's almost black eyes, panting as well, and he replied, "Damn, Cas, I almost don't wanna stop just 'cause I know what'll happen."
Cas kissed Dean again, hard and forceful and mainly teeth and tongue. He slowly made his way down to Dean's belt. He snapped and the hunter's pants were undone. Cas palmed Dean through his boxers, dragging out Dean's moans.
Dean's eyes were closed when he heard Soon...His eyes then shot open as Sam climbed back in the car. Dean looked down first to see his pants buttoned and his belt in tact. Then, he looked into his rear view mirror to see Cas calmly sitting in the middle of the back seat, his hands folded in his lap. He almost missed the angel's wink.
AH! Ok, so hope you've enjoyed what I have so far. I'm gonna try to continue this, so... Yeah. Also, reviews are welcome! Thanks~