Dean smirked. That got Sam either riled up or annoyed, he wasn't in his right mind enough to figure out which. He knew Sam didn't take compliments well, Dean was similar in that, only he was used to the ones about his appearance, it was the ones about his personality that threw him most.
"Why? Does it make it weird if I hit on my brother while he's gearin' up to screw me?" He was amazed it came out clearly and without a waver. His hands pushed at Sam's jeans and underwear, getting them down after a few rocks of his brother's hips, and Dean's mouth went dry at the sight of Sam's cock. Well, that was bigger than he was hoping for.
Wriggling a little to get one leg around Sam, hitching it over his hip, Dean kissed him for a little longer before his teeth sank into Sam's neck, leaving a very obvious hickey there. Claiming that little area for himself felt sickeningly good. "You gonna do this or do I have to figure it out by myself?"