Marlon Wayans -- Blac Chyna Has TWO Baby Bumps! (VIDEO)

Marlon Wayans didn't wait for a photog to finish his question before UNLOADING on Blac Chyna and Rob Kardashian.

We caught up with the comedian at LAX who roasted the parents-to-be, poking fun at Blac Chyna's baby bump and her ass. Check out the video ... Marlon had a bunch of Kardashian material ready, and gave us his greatest hits.