Adam Levine popped by Howard Stern's morning radio show on Tuesday (Feb. 21) and the two talked reality talent show shop, given Levine's gig as a 'The Voice' coach and Stern's much anticipated new job as a judge on 'America's Got Talent.' Of course Stern grilled Levine about his fellow coach Christina Aguilera and her curvier figure, since he has built his career on the fact that he has the guts to ask what every male is secretly thinking.

Stern asked, "Why did she get so heavy? Is she upset?" to which Levine rolled his eyes. Stern commented that Aguilera's clothes are too tight. Levine was incredibly PC about this line of questioning and attempted to sidestep it, saying, "She clearly likes talking about being comfortable with being a woman" and that Xtina can do whatever she wants. When Stern referred to the singer as plus-sized, Levine said," I wouldn't go that far." Stern's cohort Robin Quivers echoed Levine's sentiment that the singer isn't as big as Stern might think.

When Gary "Baba Booey" Dell'Abate chimed in about whether or not Stern thinks Xtina is a size 12, Stern asked Levine if he knows what size she is. His simple reply? "I am keeping my f---ing mouth shut."

Best to plead the fifth, since he has to sit next to her in the big red space chair! At the end of the day, Xtina is an utterly beautiful woman who is proud of her womanly curves.

Stern also spoke about his initial tapings of 'America's Got Talent' and again, we're beyond stoked that he is on the judge's panel. He will infuse the show with honest commentary and while many might assume he will simply shred the bad contestants, anyone who listens to Stern (as this writer does religiously) knows he is incredibly fair and takes the job seriously.

Watch Howard Stern Grill Adam Levine