Really? I remember one long tracking shot up Dean's body as he sleeps(Phantom Traveller, 4th episode) and 3 shirtless scenes altogether. Dean in Skin(though how much that counts, he started ripping his skin off right away), the top of Dean's chest and shoulders only, briefly, in the closing/opening scene of Asylum/Scarecrow and then the big "Sam in a towel" shot in Hell House. Not really very many at all compared to just about every other WB show except maybe 7th Heaven. :)

It might just be that our leads are very attractive and even perfectly normally staged shots of them look like arty gay porn. :) Let's face it, Jensen doesn't even need to try, he looks like 'arty gay porn' just about no matter what he's doing and has since he was about 17 years old. LOL