was caught offguard on the set of TV hit Entourage when he realised he'd have to strip for a sex scene.The 21-year-old hitmaker didn't realise he'd be getting naked on camera when he signed up to star in an upcoming episode of the U.S. show, and he's concerned what his fans will think of the revealing onscreen moment.He says, "It was crazy because I didn't know. I was on set and they had like a robe in my trailer and I'm like, 'So what is this all about?' and they said, 'You have a sex scene today.' I'm like, 'A what?'"I'm sure that my fans and the girls are going to get a kick out of it... but I felt crazy. I was just thinking, 'Man, what are my fans gonna say when they see this, because they never see me like this.'"