Mila Kunis Cast Her Body Double For 'Friends With Benefits'

Mila's got back. Jim Spellman/WireImage Upsetting news for Mila Kunis lovers: the sultry actress used a butt double in "Friends With Benefits." The derriere is a fake! And yet, this revelation is hardly surprising. It is fairly standard in Hollywood to hire stand-ins for stars who are skittish about flashing naked body parts on camera; what's unusual, however, is when stars get a full say in casting their own stand-ins, as Kunis did for "Benefits."

"These young ladies came in and they were in the casting room and I was there with the casting director and make-up artist," Kunis says in an interview on Ryan Seacrest's radio show. "These lovely women had to show us their derrieres and the chosen one resembled my body the most without looking like it's fake."

(Kudos to Kunis for choosing authenticity over Coco-esque lady lumps.)

The 27-year-old hottie co-stars alongside Justin Timberlake> in the sex-charged romantic comedy, hitting theaters Friday. The title gives away the premise: two friends decide to introduce casual sex into their relationship, complications ensue, you know the rest.

"It is good in theory, but horrible in execution," says Kunis. "As Justin and I put it this past weekend, you either get promoted or you get fired. It can't last very long, because ultimately somebody will get feelings. Inevitably."

As for Kunis' Rear Replacement, we can't help but recall the outrage over her "Black Swan" co-star Natalie Portman's use of a dance double in the ballet thriller. That scandal has since died down -- thank goodness, it was getting out of hand -- so now we can focus solely on brainstorming inoffensive word substitutes for "butt." Scratch that: we'll just go with butt.