Houston rapper Sauce Walka just dropped a bomb - claiming that he had relations with Offset's wife Cardi B . . . and when he broke it off, he claims that Cardi stole his flow.

Sauce Walka dropped that bombshell in the midst of a social media argument with Cardi's husband Offset. It all started when Sauce Walka dropped a new song over the weekend, and Offset thought that Sauce Walka may have subliminally dissed him in one of the bars.

Well Sauce took to social media - after Offset's accusation. And he unloaded on Offset, and his wife Cardi.

After going in on Offset, Sauce Walka turned to Cardi. He claims that she was "on his d*ck" when she was in Houston. Sauce suggests that he and Cardi had a physical relationship, and then he swerved her.

Sauce Walka further claims that Cardi was upset that she got curved, and she made a song about him - and stole his flow.

Here are Sauce Walka's exact words:

Tell the world how she was in Houston on my D*ck chasing my DRIp BUT I TRIED TO BRAKE @iamcardib and she got mad and mad a song about me. “sauce n*ggaz” “I don’t f*ck wit #SauceN*ggaz