Forgot the pass of that throwaway but you seem to have a genuine interest so I'll tell you and anybody who cares how things are from my experience.

There is monogamy but people are generally more open to hook up with others even if they're in a relationship, the key point being that they all know, the adultery and jealousy stigma just isn't really there when it's consensual. I know of a couple that occasionally meet some other guy if they feel like and they've been together for close to 4 years and are now living together.

Imagine if your group of friends all liked dick. Most of you would've probably fucked at some point and nobody would care, but you would still have a preference for one of them and would do more plans together and such because you have a higher affinity or just like to be with him, dicks involved or not. Despite the yassss screeching, straight hating clown parade pushed by the media, this is how being a fag generally works in real life, just regular male friends but with the added benefit of wanking each other if they want.

Honestly, I think many male-female relationships would be healthier if they weren't so obsessed with the notion that sex is this holy and untouchable basis for the relationship, but that's my opinion. Anyways, back to lurking, thanks for your interest.