It really should be. I mean, Sam has wanted to be noticed his entire life, and the only way he has been in Show is in a bad light (Azazel's attention, the angels he needed so desperately to tell him he wasn't something wrong and evil failed him, he's known as the boy with the demon blood, the starter of the apocalypse, etc, etc), he's lived in Dean's shadow his whole life, been a disappointment to his dad, never got to meet his mom.

I think he could psychologically have exhibitionist kinks. Sam likes to be watched and others like to watch him.

Plus I'm pretty sure he was a stripper to pay for stuff while in Stanford.