Justin Bieber isn't the only "unpunkable" teen star. Joe Jonas failed to fall for Heather Morris' scheme to frame him for a botched robbery, and he let the cameras know it!

The 'Glee' starlet set Jonas up to take the fall for helping a man steal a TV on MTV's 'Punk'd.' Jonas, being a sweetie, indeed helped the man lift the flat screen into his van ... and that's where the prank fell apart. Jonas spotted one of the hidden cameras! We guess it wasn't hidden so well, was it?

Jonas didn't play along with the prank, either. When the fake cops arrived, he knew exactly what was up. When one of the 'Punk'd' castmembers, dressed as a police officer, asked for Jonas' name, he told them he was Tom Cruise. When the cop tried to bully him into telling his real identity and giving his email address, Jonas said he'd type it in himself -- and wrote "Nice try, homeboy." Dang!

He was still a decent sport about it, though. "I came to this house to get punked," Jonas told the faux po-po, "and you guys did a pretty good job."

Watch Joe Jonas Prove He Is Unpunkable