@BeetrootsLipstick
No relationship is happy all the time, the relationships that endure are built on respect and shared values, not sex and romance.
I think I'm realistic.
I'll happily agree with you on this bit, although I'd argue that the best relationships, the ones most likely to endure, are based on all 4. Respect, shared values, sex and romance.
The problem is that even in the very best relationship, if a need is being unmet then you'll start looking for it elsewhere. In some cases people push that need down, in some cases they'll agree that it's OK to have it met elsewhere, and in most cases they'll just ignore their partners approval, and do it in secret.
My DP has no interest in long arguments about politics. That's fine, I can get my jollies by going down the pub and disagreeing agreeably with my mate. Noones going to accuse me of cheating for that, it'd be ridiculous.
On the other hand, if my partner decided that sex was odd the table, I'm fucked. We agreed to be monogamous, and people are going to be really disapproving if I go and sleep with my mate. I'm only 40, I'm not ready to give up on sex yet. So my choices are to leave, hide it from my partner, or get some serious side eye from people I know if they find out I'm in an open relationship.
Most things in life you can get from.other people, even if you're in a committed relationship. Sex, romance, they're the things we're expected to be monogamous for, and if one person takes it off the table, the other is left with no good options.