Picking favorites isn't easy -- and Nick Cannon is about to be in a very uncomfortable situation regarding this difficult action. Making matters more awkward: It has to do with the mother of his children.

In a sneak peek from this weeks' Wild 'N Out episode, Nick is in the "Plead the Fifth" hot seat as Rip Micheals takes the microphone.

"Great father, by the way" Rip begins, as Nick expresses his gratitude. It's always best to serve up a lovely comment -- before going straight for the jugular.

"Question is simple: Who is your favorite baby mama?" Rip inquires (ahem, Mariah Carey and Brittany Bell).

How does Nick react -- and does he offer up a reply (or PTF)? Watch the cringe-worthy clip below, and don't miss the entire Wild 'N Out episode on Thursday at 11/10c!