Is cheating acceptable?

No it is never acceptable...think about how the other person would feel, you wouldnt that to happen to you right? What does the other person have that the current person your going out with doesnt? I feel there is no reason to cheat on anyone ever and if you do cheat they should leave you on the spot. cause obvioisly you didnt love them enough to stay with them and only them

People that cheat like that already have lost respect for you and all others, they don't care how you feel, and normally can't be put in that position, due to not really feeling much of anything anymore. Of course, people do make mistakes every once in a while, but it doesn't make it acceptable. But some cases can be forgiven, since everyone is different, and every situation is different.

@Honō no Gaki Then, it's not cheating. It's swinging.

Not good, it killed me as chinamini for long time.But also damaged my soul, I really understimated my capacity to live the role, to the point that hurts like real, like a lens made of transparent plastic also concentrate sun to burn things into fire. But it would never hurt me that bad If I knew, or accepted that I was the only one totally in love with him beforehand...

I dont cheat but I'd rather break up with the girl than cheat on her. Whats the point in wasting her time, when she can be out there finding a guy that actually cares enough not to cheat.

Unless its an open relationship from the get go, no it's not. If you feel you need to do such a thing, either break up with the person your with first or don't get into a monogamous relationship to begin with.