Is slapping another girl's butt a cheating behavior?

Anonymous
My boyfriend broke up with my friend whom I was close to and he started dating me. He claims he never loved my friend and he has stronger feelings for me than her. So I should assume that he would be faithful right? We are together and he practically moved in with me and spends all his time with me not to mention we are co-workers at the same shift. We were all hanging out with my roommate when my boyfriend slapped her ass, groped it for a bit and when she turned around shocked he smirked and said, "Judging by that smirk on your face, you liked it" At first I didn't care and I told him that was disrespectful for my roommate's sake but now that I think more about it, it bothers me that he might cheat on me eventually. What do you guys think?
Is slapping another girl's butt a cheating behavior?
8 Opinion