This is one of those questions that everybody who’s thinking of leaving beats themselves up about:
Am I really going to leave over ‘sex’? Can’t I just take a cold shower and get over myself? Is it that important? Am I some kind of sex-mad perv? Perhaps my partner is right when they say ‘nobody else our age is doing it either’? Perhaps I should settle for no sex, rather than rock the boat and upset everyone else? Won’t I look really shallow if people hear why I left? Everything else in the relationship is ‘okay’, so can’t I just do without sex?
A sort of imposed victim-blaming.
The trouble is, sex and intimacy is something to be shared. It isn’t passive, or one-sided. It’s not something that one party can half-participate in as a compromise. For many, it is like food. It’s needed regularly and without it, the relationship will die. Afterall, what differentiates you as couple from any other two people who know each other? You trust each other and share fun. Well that could be a friend. You live together and have joint responsibilities for bills and chores. Well, that could be a flatmate. But intimacies and sex? Well, that’s lovers, partners, married couples.
That’s when the resentment and anger starts to surface. When you realise the senses of rejection, loneliness, belittling, minimising, ridicule, shame, depression, etc. are all being imposed on you by your partner. That they don’t actually care for you anywhere near as much as you’ve given them credit for. As others have said, how much does your partner really love you, if they don’t want any intimacy and sex with you?
Even if they graciously suggest you get sex elsewhere, that doesn’t work for many of us, as we can’t / don’t want to separate love and sex that easily. It also forces the rejected person into breaking their marriage vows / cheating and is a further emphasis of their feelings of ‘I don’t want you, so can’t you go bother somebody else?...’ In any case, that is an abdication of their responsibility to either engage willingly in intimacy, or if they don’t want it anymore (which is their right) to be honest and equitable about the end of the relationship.
So yes, a relationship can quite legitimately end over sex, but fault is often wrongly apportioned.