Well I don't know if this makes a difference, but when I was married, I cheated on my husband. I just was not happy with him. I was not in love with him.
Meanwhile, I met a man that gave me everything I wanted (I thought). He seemed more like my type of guy. I was just open and did not even care that I was cheating, at one point. I cheated for about a year before my husband found out.
I hurt my husband, who was a good man. He loved me. I could have at least been open and honest with him instead of cheating behind his back. That "other guy" is long gone now and I found someone MUCH better
but I don't regret that I was with that other man - just that I did it for so long without keeping things real with the man I was married to.
But, that does not make me a cheater for life. It just showed me that I need to be more picky and I also learned a lot about myself and what I want in a man.
Now, granted guys do think with their loins and not their brains many times, but I really don't think a guy is always a cheater just because he did it.