I hate it when people say things like once cheater always a cheater or if some is going to cheat they are going to cheat. Especially when these people have not been cheaters, it's really not that black and white and you haven't the faintest idea what your talking. I'm not saying go out and cheat so you can say you've experienced it and make a useful contribution tot his thread, but you just all sound so high and mighty thinking your so much better than 'scum' like me. I understand that some of you make have been in the receiving end of cheating and I can understand that hurts, but it still doesn't make you able to see it from my point of view.
I will freely admit that I cheated on my boyfriend, it's not something I'm proud of, it's not something I will ever try to justify it to you, him or myself, but it happened, he forgave me and we're past it now. I cannot say why I did it, I don't even know. If you are one of those people who say 'it has nothing to do with alcohol' stop reading now. I was very drunk every time and I can honestly say that being teetotal has made a difference.
It's not about getting away with it, I never expected to get away with it, but then I also never expected to do it either, I didn't go out thinking tonight I am going to cheat, the thought didn't enter my mind and its not like I was going up to guys with the intention of cheating, if a guy a approached me, I guess I just didn't know how to say no, that's if my drunk self was able to say anything at all.
I'm not trying to make excuses I'm just trying to answer the OP's question and I'm obviously not doing very well.
But on the subject of once a cheater always a cheater, I cheated after 18 months with my boyfriend, I have not cheated (and don't intend to) in the past 5/6 years (not through lack of opportunity), I could have if I wanted to but by keeping my head clear and learning to say no and mean it I have stayed faithful and will for the foreseeable future. Just because I did it and managed to keep my boyfriend does not mean that I'm prepared to risk it again and just as an end note if you're going to tell me I don't love him, don't bother, you're another one who doesn't know what you're talking about.