Khamzat Chimaev is calling BS on Paulo Costa's claim that he slid into his girlfriend's direct messages ... telling TMZ Sports that's just not how it went down!
"Why should I DM somebody's wife, bro?" the 31-year-old UFC star said Wednesday from a pre-fight workout in SoCal.
"She DM'ed before the fight, when I announced the fight like, 'Khamzat, please don't take it seriously. We're just trying to make money and hype.'" Chimaev recounted, before revealing what he said back.
"I don't care what they are, I'm just going to f*** your boy up, and that's it.