Kiss Prince Download 'Kiss' on iTunes
The 'Twilight' star is such a huge fan of the X Factor finalist that he has vowed to turn up to the studios wearing a 'Vote Wagner' T-shirt if he makes it to the final.
A source has said Robert has said "Wagner is "the sort of guy you'd do a drunken duet with at a family wedding. I love this guy. He doesn't have the best voice, but he enjoys what he does and I respect him for that. It's great just to see him wind Simon Cowell up."