Objectification. It happens to men, too.
I'm not saying it happens equally to men or that it has the same kind of societal ramifications for them. But being shown physical ideals to live up to isn't exclusive to women. That's why I love this parody underwear ad. None of that stunt-y, Apatow-ish "I did a gay thing. Let's all laugh because GAY!" humor. Just two dudes actually being cute and funny and comfortable in their underwear together.
Body acceptance: CHECK.
Normalization of homoeroticism: CHECK.
And one final note about male body positivity:
SPARKLE ON, YOU CRAZY KIDS.