Magic Mike's Alex Pettyfer Proves He's Got Back

Wondering if we should nickname Alex Pettyfer "Happy Cheeks?" Check out that yellow happy face on his right butt cheek!

The 21-year-old Magic Mike actor was happy to show off his muscular rear-end while on the set of the Steven Soderbergh-directed stripper film.

Channing Tatum, who also stars in the flick, has been flaunting his sculpted physique, as well ... but unfortunately the G.I. Joe star hasn't been this cheeky.

Magic Mike doesn't hit theaters until next year, but we're excited to already catch a glimpse of Mr. Pettyfer's goods.