Well, here is something we never knew we needed: Jennifer Aniston and Jimmy Fallon switching lips.

Janiston (our new nickname for her, BTW) and Jimmy Fallon swapped mouths on 'The Tonight Show' last night (Jan. 21), each making the other say ridiculous things about Billy Bob Thornton, Bonnaroo, the Super Bowl and more. (Because when you flip lips, these are clearly the topics to discuss.)

But as it turns out, it didn't really matter what they talked about -- because besides the whole hilarious lip-flipping thing, the funniest part of the segment is Aniston and Fallon trying so hard to keep from laughing -- and failing miserably. Because when one laughs, it's the other person's mouth laughing for them. Or something.

Watch Jennifer Aniston and Jimmy Fallon flip lips in the video above.

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