Simone Bilesreceived a lap dance on stage at a "Magic Mike Live" show in Las Vegas on Thursday night ... and video of it, obtained by TMZ Sports, is STEAMY!!
The gymnastics star took in the performance at SAHARA Las Vegas ... when about mid-way through the act, she was pulled on stage with another woman.
It didn't take long for the shirtless dancers to rope the two ladies into their bit -- 'cause the guys grinded all over the girls ... and, at one point, one of them even picked up Biles and took her to the floor.
The whole routine lasted about two minutes -- and it featured tons of gyrating, lots of hip thrusting, and plenty of touching.