betrayal for a reason is okay. but what reason for betrayal is the real question.
you forgot about shinichi kudo and inuyasha. those 2 actually got NTR.ed right?
i prefer the woman in a happy life.
if the man is a moronha. and dense type of a guy. it's okay for me.
not okay if it start with a rape, mind control, blackmail.
something like this also acceptable for me
https://hanime.tv/videos/hentai/uwaki-to-honki-1