In the beginning of Bloody Mary, Sam and Dean go to check out the corpse of BM's first victim in the episode. They have to bribe the ME guy because he won't let them in. Sam gives the guy a $100 and Dean gets pissed. "I earned that money!" and Sam's all, "you won it in a poker game" while Dean does a 'yeah, and what's your point?' look. So Sam was holding Dean's cash. And freely handing it out. xD