i think infidelity is complicated.
i don't think there's anything moral about it in the slightest... but i try to not pass judgement.
Long term and married relationships can result in people feeling suffocated and trapped - and to end them would mean losing their best friend, losing their home, possibly losing bets or access to kids. Your finances get torn to hell.
What do you do when a partner stops trying to be attractive for you?
What do you do when a partner stops wanting to explore sexually with you? or you find down the road you hae continued to grow sexually and your partner hasn't? Or that one of you has grown cold sexually?
Most infidelity generally stems from the fact that one person has communicated endlessly to another that they want something and that person won't or can't meet them half way.
A person feels if they stay with the way things are - they have a life of misery.
And if they leave - they have a life of misery.
I don't excuse the cheater - but i think a lot of people talk without knowing what a 5, 10, 15+ year relationship can be like when it goes sour in certain ways. Things taht are really important, become these silent elephants in the room, subtly nibbling at your relationship.
People need to feel wanted. Monogamy is a social construct that we're not programmed for. And it really takes two people working REALLY REALLY hard at it, endlessly, communicating, not putting walls, sometimes taking one for the team and not doing so begrudgingly, not taking the other person for granted, and realizing the attraction and sexuality don't end when the ring gets slipped on a finger.
I would say there are some bad people out there who are serial cheaters who don't have an ounce of empathy to them, who are narcissistic and purely self serving.
But i would bet most people out there who make that choice don't do so easily. It might be the wrong choice - but i t weighs heavy on them.
I don't cheat - but i've thought about it, i've even sought out to. And in the end rather than cheat i decided a very sad attempt at suicide was a better option b/c my sexual needs have a profound emotional impact on me when they're rejected, not met, ignored, belittled, or told that it makes me out to be a freak. No option sounded great to me. Leave the woman i love deeper than anything? lose the most important relationship to me b/c she won't meet my needs? Lose my house? wreck my finances? lose a pet i'd cry over for weeks b/c i love her so dearly? have my entire future shatter before my eyes by breaking up with her? Or cheat and get those needs met but risk hurting that person i love so deeply? Both sounded equally awful.
No one knows the misery a relationship can be, to someone you can't bring yourself to leave b/c you love them so much. Because of the fear of being alone. THe pressure to not destroy your life.
So when people cheat - i don't support them. not in the slightest. but i try not to throw stones either. Going through life feeling like the person you love doesn't want you, and you're stuck in a corner where no one will ever show they want you ever again... just makes even the best relationships feel like a prison sentence.
I don't know if that's what my sibling has going on. She's a bit of a self centered asshole who has no empathy for anyone. But i've been there. I've wanted to. SO i can't judge.