And not to sound sexist, but I see this issue happening more so when it's the man cheating on the woman I noticed that the wife/girlfriend and the mistress both get blamed for the man's choice to cheat. Whether it's because she "let herself go", "boring sex life" or the woman's behavioral problems etc. That he would rather step outside of the marriage rather than fix the problems. and then it also becomes the mistress's fault when people say things like "she knew he was married/in a relationship" "she's a home wrecker" so did he as well he knew he was with someone all along as well and it was HIS choice to step outside the relationship/marriage he broke the marriage vowels and not her it doesn't matter who came on to who or who was tempted first cheating is a CHOICE not a mistake.
And I also understand that in some situations the affair partner is totally innocent as there are cases where the cheater lies about being single/married only to find out it was all a lie.
But no matter what the reason is a person chooses to cheat on their spouse/partner, why does the cheater seem to never take responsibility for their actions but chooses to blame everyone else instead of themselves this goes for both men and women.