Stars in Skivvies: The Sexiest Underwear Ads Ever

Not that we really needed an excuse to look at these hot celebs in their unmentionables, but this week marks the 20th anniversary of Mark Wahlberg's iconic strip-down for Calvin Klein so we had an extra-good reason

MARK WAHLBERG

A lot has changed in the two decades since Marky Mark posed in nothing but a tight pair of Calvin Kleins. He no longer goes by Marky Mark, for one; he ditched modeling for acting; and his funky bunch now consists of four kids. One thing remains the same, though: Those incredible muscles.