The X-Men films really should be called the exploitation of Hugh Jackman. Ever since the first installment -- after the actor beefed up for the role -- Jackman has been appeared in fewer and fewer clothes. In X-Men Origins: Wolverine, Jackman was stripped down for a sequence which showed him emerging from a water tank. While the movie shows plenty of the actor's chest, the behind the scenes photos show off a bit more thanks to a nude, skin-tight swim briefs he wore for filming.
While the scene initially featured a shot of his bare butt, it was ultimately cut from the film. However, the franchise made up for it by showing off his entire backside in the latest installment, X-Men: Days of Future Past. After Wolverine is sent back in time, he wakes up naked in bed and takes a moment to check out his '70s era build.
If you still haven't seen the film, this scene is worth it.