(deep breathe)
I was the OW many many many years ago. I was 19 he was much older. I thought he was sophisticated, he treated me nicely, he was gorgeous, he ticked all the boxes. Except he was married. Me, in all my infinite teenage wisdom, decided to overlook this "small" fact. I didn't dislike his wife or children, they didn't even come into my thought process, I was too busy being swept off my feet.
In my situation, his motivation was clearly that I was young, gullible and he could spin me the the old line of "my wife doesn't understand me", be available as he wished and I accepted it. My motivation was he swept me off my feet, I liked him alot and I felt he must really like me to risk his marriage on it.
In hindsight I was naive, foolish, inconsiderate, selfish and immature. Have my views changed? Of course. I have never entered a relationship with a man with a partner since nor would I again. I don't approve of it, I don't agree with it. I think age and life experience accounts for alot in my particular situation.
I don't understand the motivation of the OW who is older than I was and of an age to really have empathy with the cheated wife. I always assume it must be money or lust.
As for men, it seems they want to have their cake and eat it too. I suppose they are just thinking with their penis or too weak willed or shit scared to end their relationships.
Neither the OW or the cheating party is fully to blame. The only innocent is the cheated party. I know it feels like shit as my ex DP had an OW. I consider it karma for my actions when I was younger.