OP it takes a certain type of person to have an affair - completely self-centred and devoid of empathy.
I've known 2 women who had affairs - one was married and shagged her husband's brother several times, got her eldest teenage daughter to get her the MAP and lie to her dad about it, then had an affair with someone else who she later left the marriage (and the children) to be with. That was my mum, and I was the eldest daughter.
The second was my SIL (husband's brother's wife). She was the OW while BIL was still married to his first wife. They eventually got married and a couple of kids later she left him for someone else.
Both women were/are pretty cold when it comes to empathy. My mum pretends to empathise, but she's a narcissist and is completely fake. (She also voted for Brexit because people were infiltrating our country
). Ex-SIL was also completely devoid of empathy and was a judgy cow.
The men in this situation, my dad is no angel, but he's a decent guy who tried his best after being a SA survivor and pretty abusive childhood. Brought up my little sister alone whilst my mum didn't want to know and out of both my parents is the solid one, the one who I know I can rely on.
My BIL is a dick and pretty much deserved whatever ex-SIL threw at him TBH. 8 kids to 5 different women, doesn't see 6 of them and pays for none of them.
My view is probably jaded after having to lie for my mum whilst knowing she was shagging my uncle, and then her OM. But I do know I couldn't really associate with someone who had affairs, not my type of person really.