I have been cheated on numerous times by my fiance with his ex that knew about me the whole time. My question is what are the reasons that the "other woman" would help a man to cheat with her on his wife or girlfriend that she knows about?

Pure selfishness and spite. My almost ex works with his ex and occasionally still goes to see another ex from like ten years ago, supposedly purely platonic, but not so sure about the one he works with. I've wondered about this myself and what if and not having been the other woman and having been cheated on myself, I can only assume to continue to cheat with an ex is pure selfishness and imagine it makes it more enticing for her because she knows she's stealing his time away from you. She can kill two birds with one stone so to speak--she can hurt both of you at the same time--hurt you by cheating with him and hurt him by being the cause of the breakup between you. Neither one of them deserve to take up any more space in your mind. You deserve to be treated with respect. Kick them both to the curb.

Personally, I don't think that it even enters the other woman's head to think about the girlfriend or wife. Yeah, she knows about her, but she is too weak and selfish to say no. Its like when you are on a diet and someone offers you chocolocate. Some people can't resist and they go for it, hence why you hear the other woman often say that she didn't mean to hurt the wife or girlfriend, but she assumed that if the man is cheating he is not happy or even believes the crap he gives her about being mistreated and not sleeping with the wife anymore. It all comes down to pure selfish lust. Basically, human beings are not supposed to be who we have become through social conditioning, it actually goes against our makeup to be monogamous. Our conscience should tell us what is right or wrong, but not everyone listens to it.

I have been doing some searching on the net to find out what the "other woman" thinks and why she does what she does in these types of relationships and they all seem to blame the girlfriend or wives about the mans infidelity. Almonst 90 percent of the posts I have read by these other women say that if the wife or girlfriend was doing what she was supposed to do then the man wouldn't cheat. I hate the fact that these women don't have enough self respect to turn down a guy who is unavailable and find someone who is. The thing is the other women claim they are tired of dealing with him after years of being in the relationship only to find that the man won't leave his wife or girlfriend. I mean my thing is why even go there with the man if they know from the begining what type of man he is? Where are these women's morals and standards? I know I seem like I am bashing the other women but this is not about the ones who don't know about us....this is about the ones who do and choose to engage anyway.

I'll admit - I've been the other woman to a guy who was dating (not married). Here were my thoughts at the time:

1) Whether what he says about his partner is 100% true or very exaggerated, it's obvious that they are not compatible, and it's just a matter of time until they break up.

2) By showing him how good he COULD be treated, maybe he'll wise up and end the farce of a relationship that's holding him back (because, you see, I care SOOOO much)

3) He's broke and I can fix him - which is, of course, totally false, but it seemed like he would confess to me the things he couldn't say to his g/f. Which means now I know him even better than she did, right?

Given those points, I confirm previous posters' comments:
1) The 'other woman' doesn't give half a thought to you - her relationship is with the cheating man, not with you - you are not her problem.
2) Who knows a guy's flaws and good points better than an ex? He's already been judged if she was the one who broke it off, OR, if he ended that relationship, maybe she thinks she has a chance to steal him back?
3) Yes, he's a dog, all men are dogs, all men have problems and women think they can help, right? Cheating is just a different problem...

I'm not sure if anything is really gained by understanding the 'other woman' - but that was my take and honestly, it's not an experience i'd care to repeat. I hope this helps. AND I'M SORRY to all you out there who were CHEATED ON!

The thing about it is...maybe the other woman doesn't realize that the majority of good women in the relationship with the cheating man are doing everything to keep him happy at home. Maybe it's like the other posters have said that he is selfish and wants it all from different women. Some men do actually have feelings for the other women. Men need to grow balls and break up if they want to do things with other people. In these days and times STD's are so prevalent and growing a fast rates that it is getting to a point where cures are almost impossible. Most people don't know they have anything. People need to realize this and think before they act. I will admit that I should have left my fiance...it's hard to leave knowing you have to start over and not knowing what that person has or is capable of doing is scary in this day and age.