Does anyone have any stats around this? What proportion of relationships over a certain number of years involve cheating?

Has anyone been in a relationship that has survived cheating? I'm talking about serious relationships, stuff where you both knew monogamy was expected and had been together a while, a year at least.

Has anyone been in an open relationship? Didi it work? If so, why? If not, why not?

I've been "cheated on" and it genuinely doesn't bother me, but the other guy wanted to end it so I let it go. In my experience, most people are incredibly sensitive about sex; despite being perfectly capable of imagining and having loveless sex, as soon as they're in a relationship suddenly it's impossible to love someone and fuck someone else, even just once while drunk.

But no, monogamy is not an unrealistic expectation. It's not hard to keep your dick/foof in your pants.

I'd say so.

Unless you have no self control what so ever, no.
If you feel the need to sleep with someone, end the realtionship your already in.
I don't see why people find this so hard.
Why cheat?
You obviously like the person you want to sleep with, you obviously don't love the person your with, if your even considering cheating.
So just end it, and do what you want to do, that way no-ones feelings are getting hurt.

I had a 7 year realtionship that ended in cheating.
saying that though, I had a 2 and a half year realtionship that was pretty much perfect and no cheating was involved at all. It just got abit to "cosy" so I ended it, we are still best friends now.

The likeliness of monogamy depends on your partner. It might be very realistic to expect monogamy of one person, and not realistic to expect monogamy of another person.