It's been a while since someone posted a comment, but I'm new to the site and this topic is new to me, so I'll throw my hat in the ring.
Cheating is a state of mind, for sure. But there's a difference between a one nighter and an on-going affair. Generally, a one nighter is purely physical. Two people meet, find each other hotly attractive and feel the need to have sex. It's not planned and it happens based on a set of situational circumstances.
An on-going affair is a much more serious matter. Generally, an affair involves emotions and usually someone gets hurt.
I think a one nighter can be forgiven, as long as it is not a routine thing. If one partner continues to have one nighters with different people, that person has issues that need to be resolved.
An on-going affair is proof that there are greater problems in the relationship. If the problems are so deep that one partner has entered into an affair, there may be no repairing the relationship.
So, to answer the main question that was asked...it depends. Personally, I have a rule. If someone is in another relationship and they cheat with me, there's no way I'll build an emotional bond. If they cheat with me, they'll cheat on me.
I'd never try to tell someone how their relationship should work. But for me, I can't abide cheating. Mostly because I would feel guilty. I'd wonder if there was something wrong with me, and if there was, why wouldn't she tell me about it. I've never cheated, or been cheated on to my knowledge. But if there was something that I couldn't provide for her that she needed to get elsewhere, then maybe I'm not the right man for her.
I'm not trying to stake the moral high ground here, but I've had the chance to cheat, with no worry of her finding out, and I couldn't even get aroused by the idea. But if I cheated, I'd tell my girlfriend and let her decide what she wanted to do with me. If she couldn't forgive, I'd understand.
I guess at my age - just let me watch at least
I like curious2c's comments. I'm a relationship counsellor and obviously have seen as clients both male and female cheaters. Whether a couple stay together seems to depend upon whther they are prepared to look at the issues behind the cheating and a) talk about them b) change what can be changed c) agree to put it behind them and move on. This is a simplistic view of a complex subject about which many books have been written.
In my experience of being cheated on twice now. I gave her a second chance going along with her saying it was a one time thing and forgave her. Not even a month later she cheated on me again. I say once a cheater always a cheater. Better to kick them to the curb than to be dragged thou the heartache twice!
I say keep it to yourself. It's none of my business!!! But once a cheater always a cheater. So don't tell anyone.
once a cheater always a cheater, can't trust people- DTA