Dean snagged hold of Sam's arm and tugged him down before he could go anywhere. "Not so fast, Gigantor." Hooking an arm around Sam's shoulders, Dean pulled him into a kiss. The guilt was there, but he didn't regret it, which was why there was so much guilt on his part. Even so, he wasn't going to let that get to him and ruin this.
Running his hands through Sam's sweaty hair, Dean kissed him slow and deep, taking the chance, now they were done, to really explore his way around Sam's mouth. He thought he knew everything about Sam, but there were little things he had learned in this. The taste of Sam's mouth, the size of his length when it was fully erect, the sounds he made when he was balls deep in someone. They were nice things to file away for later.
Ending the kiss, he sucked a little on Sam's lower lip as he pulled back. "Get the water runnin', I'll come shower with ya." Unless, of course, that was too couply for Sam and all his brother had been looking for was sexual gratification.