Cheating on my fiance

I am 29 years old I have been engaged for about six months and been dating this girl for just over four years. Things are generally good between us and we are good for each other in many ways. She is the sensible one and I'm the fun one if you like. Anyway, recently because of work, we've spent quite a bit of time apart. I just can't stop looking at other women and I often have fantasies about other girls that I meet. Without being arrogant, I'm a reasonable-looking bloke and I'm very sociable and like telling jokes so I do get female attention. One night while we were away from each other, I went to a bar and got talking to a girl, I told her I was engaged but I continued to flirt with her. I wanted to kiss her but she refused as I'd already told her I wasn't single. This happened a few months ago. I promised myself that I'd never do anything like that again. But now I'm constantly thinking about other ladies and have this thought going on in my head to have sex with just one more lady before I get married (plans are in the next year or so). I have cheated on her once but it was a long time ago (6 months into the relationship) and it was just kissing, not sex. It was the first time I'd ever done anything like that, and I remember how guilty I felt after that. I almost broke up with her but didn't tell her about this episode. I get these immense feelings of guilt for my actions and I just feel terrible (even entertaining suicidal thoughts). I keep promising myself not to do anything but I'm just so sorely tempted. It's so unfair on her as I'm sure she's totally faithful to me and doesn't have such thoughts. We are also sexually very compatible so it's not that problem. I do love her but I just can't quit these thoughts. I guess I'm just a bad guy maybe. I don't want to split up with her as I need & want her in my life but I can't keep behaving like this while we're apart. When we're together, it's nowhere near as bad (although I still fantasise about other women) I don't flirt. What should I do about this problem? It's eating away at me and it's so unfair on her. Thanks for any advice you can give.

Hello! I read your post and see whats going on. You are human. With that, innate human nature (especially in males) are to not be tied down. What you are feeling is 100% natural. However, marriage is not natural, it is a more civilized union than what our early ancestors engaged in. So, us humans are stuck between our nature and evolved social expectations for a civilization. You can chose to either commit to the marriage, and allow these to be thoughts and not act, or you can go primal mode and snub the commitment of marriage. Those thoughts will not go away, like I've said its completely normal, but if you choose to commit to this girl, be good to her and have the self control to not act on your impulses. If you choose to continue with the relationship and those thoughts come up, just remember it is part of the primitive mind, not the more evolved, and just acknowledge that. Good luck!!!