UFC's Paulo Costa Demands Israel Adesanya Rematch After Humping Incident

UFC middleweight Paulo Costa wants another crack at Israel Adesanya ... calling the champ "human trash" for air humping him after Saturday's fight.

The Last Stylebender easily handled Costa with a 2nd-round TKO ... and promptly hit him with an NSFW celebration by getting on top of him and thrusting.

Costa says he had no idea what Izzy was doing at the time ... but now that he was able to see the footage, he's demanding revenge in a vicious video with the caption, "Adesanya is human trash. This has become a grave situation !"

"I disapprove 100%," Costa said in the video. "To me, this is mortal now. Nobody can stop me.

"I want my rematch and you know I will wait for you."

Costa goes on to say "something happened" before their big fight ... and he will be fully prepared the next time around.

"I'm not [making an] excuse here to my people, to my fans. but I will be 100% to fight him and to make him pay. That's my words. Save my words."