Originally Posted by greenchild90
Well, as far as I know from what both of them have individually vented to me (not assumptions), she is not comfortable with him being "poly", and he is not comfortable with giving up his "poly" lifestyle. However, both of them are clinging to whatever relationship & commitment they have, and don't seem like they necessarily want to give up each other as people.
I am going to say that especially in poly, when a person isn't clear about their wants and needs & just kind of does what they want without first being very clear with their other partners (even though it's obviously causing problems) they end up being drama magnets. He seems weak willed, and that's not something I could handle from a partner, lots of problems in poly come from shitty communication, and this situation seems to have it in spades.
I'd also ask them to stop venting to you, and say that you'll be glad to talk to them about their relationship once they hash things out. I think it's immature of him especially (not her so much since you're friends) to be complaining about their dynamic. I don't know if he's venting just to vent, or venting in order to seek advice, but if it's the first one it's bad and it's going to undermine your relationship with your friend. I rarely would find it appropriate to vent about my partners to each other, and I wouldn't let them vent to me more than once about a particular issue.
It's irresponsible for somebody who wants to be poly to get into a relationship with somebody who wants monogamy without having what that is going to look like at least somewhat sorted out. He doesn't really sound ready for a serious relationship in general, let alone poly. If he finds it easier to "cheat" with you, he might find it easier to cheat on you instead of being forthright about what he wants to do with other relationships.
Then again it doesn't sound like you are hoping to be with him all the time, so maybe you're fine with that, but I do want to say he sounds like he has some relational skills he needs to learn.