Karrueche Tran -- If I Bump Into Chris Brown's Baby Mama in L.A. ...

Chris Brown's ex-girlfriend could be bumping into Chris Brown's baby mama real soon -- and Karrueche Tran wants us to believe she'd be totally cool with it.

We broke the news to Karrueche Wednesday night ... outside BOA Steakhouse in West Hollywood ... that Chris wants to move Nia Guzman out to L.A. so he can be closer to baby Royalty.

L.A. is big, but not that big when you run in the same celeb circles -- so, what happens if KT runs into Nia at the club? Watch Karrueche's answer -- her mouth's saying one thing, but her body doesn't seem to agree.