Adam Levine and Christina Aguilera

While ‘The Voice’ co-stars may bicker on-screen, Adam insisted they have a close relationship and he won’t let anyone say anything bad about the singer, who has recently come under fire for her fuller figure.

He told People magazine: "It's not cool. I've never liked it. I think it's horrible and I'll totally defend [Christina] when people say things like that because it's no one's business.

"The one thing about the culture right now, celebrity culture particularly, is people feel like they can just say nasty things about other people whether it's Christina or whether it's me. Of course I have her back and of course I defend her."

Adam also revealed that while the couple may disagree on the show, once the cameras stop rolling they forget their arguments.

He said: "The fights that everyone thought we were having were fictional. We never hated each other. We never had these secret battles that everyone thought we were having."