!! OMG, his butt: Zac Efron give us a CLEAR VIEW of dat naked booty in ‘DIRTY GRANDPA’ !! » Posted By Igor On Tuesday, January 26, 2016 | category: Candy | 13 comments Apparently, this film is doing well at the box office… Who would have thought? The reason? Well, Zac Efron does dance almost fully naked. Check it out in full view after the NSFW jump!