Amber Rose & Blac Chyna -- Baby Mamas' Night Out ... At the Strip Club!

Wiz Khalifa and Tyga's exes refuse to take a back seat to them when it comes to making exotic dancer support payments (just sounds classier) -- cause Amber Rose and Blac Chyna went big in an L.A. strip club.

The girls hit up Ace of Diamonds in Hollywood Monday night ... the same club where Wiz went crazy a few weeks earlier. Once inside, Amber and BC bumped and grinded with some of their ex comrades-in-lucite.

Our sources say both women were paid for their appearance at AoD -- though it's unclear how much ... some of it went back to the employees. We're told they rained $10K on the strippers ... right on par with what Wiz and his crew spent.

Gender equality exists in strange places.