If you thought Kanye West and Bianca Censori's red carpet stunt at the Grammys was shocking ... well, things got even crazier at one of the after-parties they attended -- with the couple getting down and REALLY dirty!

TMZ obtained photos/videos showing the famous lovebirds at influencer Justin LaBoy's Sunday night shindig near Hollywood after Kanye and Bianca made an eye-popping entrance at the Grammys with Bianca stripping naked for the cameras.

The two left the Grammys soon after posing for pics on the red carpet and before the event even started, popping into LaBoy's soiree later that night.

Check out these stunning videos shot at LaBoy's get-together ... Ye and Bianca are grinding on the dance floor while licking each other. Kanye also grabs Bianca's butt cheeks in a mesh thong bodysuit.

Other clips show Ye and Bianca chatting, smiling and drinking while also hanging out with friends. At one point, Bianca parked her rump on the DJ table and belted out Adele's hit, "Rolling in the Deep."

There's a bunch more footage to sift through ... trust us, it's worth the watch.