Madonna -- Ass Cheeks Out ... Squeeze 'Em Easy!

Madonna's ass probably couldn't make it in a Nicki Minaj video these days ... but that's not stopping her from exposing it like it's 1992 again.  The 56-year-old arrived at Staples Center for the Grammys in a sexy matador outfit, and decided to…

Sarah Mutch Sarah Polley Sarah Shahi Sarah Silverman