Credit: Getty Images Photo: Adam Levine at NBCUniversal’s 2012 Golden Globes After Party

Voice judge Adam Levine was visibly uncomfortable on Howard Stern’s talk show when he guested on Tuesday.

The usually outspoken musician was struck mum when the radio jock asked him about his fellow judge Christina Aguilera’s weight.

“I’m keeping my f**king mouth shut,” said Adam, as the hosts speculated as to whether Xtina was above a size 12. That’s probably a safe choice, given that Adam will be spending the next few months alongside her on The Voice.

Check out the vid below to hear Adam defend (well, kind of) Christina’s right to wear tight clothes and discuss his relationship with supermodel Anne V., who joined him for the interview.

Warning: This video contains language not suitable for moderately conservative work environments.