All this talk about Justin Bieber's butt has got us thinking about man butts in general. (As if we don't regularly have them on our minds.) Butts are so underrated, so we are here to hype them up. Let's look at our favorite — and sexiest — man butts we can possibly find all in one gallery. Keep reading because the asses just get hotter and hotter, there's no buts about it . . . Leave that computer screen dim because this stuff is NSFW.