Should Kayla give her boyfriend another chance after what he did last weekend or was this an undisputed act of infidelity?

Dear Keke,

I’ve been with my boyfriend for five years and we’ve been living together for six months.  Last weekend, he went out with his boys, got really drunk and ended up getting a ride home from a girl who has wanted him the entire time we’ve been together.

Apparently my guy can’t control himself, because he ended up kissing her on that ride home.  Of course this blew up into a huge argument since I consider kissing another woman cheating.  He said it’s not because they didn’t sleep together. I threw him out until I can find another place to live but he’s begging for another chance because he insists what he did wasn’t cheating.

Do you think I should give him another chance? What’s considered cheating?

Kayla in Eagle