Cheating is oral or fucking.. Making out with someone is not cheating, but highly frowned upon in my book... But I wouldn't leave someone for it... Now I'm talkin' a quick heat of the moment hot dancing mini make-out.. Not hour long make out session or in the corner... That's when it starts to get to be rude
But I still wouldn't be completely betrayed by it.. Just really pissed.
I am a very open minded person & I trust my partner to not hurt my feelings by doing things that make Me feel uncomfortable.. I don't mind dancing and flirting, as long as things are made clear to the person that my partner is taken.
Edited for clarification