Conor McGregor: I Was COMPLIMENTING Khloe's Ass ... But Floyd's Still a Bitch (VIDEO)

Conor McGregor wants to set 2 things straight -- he LOVES Khloe Kardashian's "big fat ass" ... and thinks Floyd Mayweather RAN SCARED during a recent trip to Las Vegas.  We got the UFC superstar leaving Mastros Steakhouse in Bev Hills last…