I have to agree with the last poster on this one.
It doesn't sound like she's as poly as she claims. I've been poly my whole life and frankly I can't imagine.
Just the fact that my husband is willing to TALK about it to me made me MORE affectionate with him and brought back a strength and love and power to my feelings for him-because I could be ME honestly with him in conversation-forget the acting on it part.
He's trying to open up to the idea-so we spend time with the other man periodically-but only AS FRIENDS-because I DO love my husband and I NEED him to be comfortable as much as I need to be honest about who I am and how I feel.
This partner of yours seems to be... well no ill regard intended-but a bit selfish....
I think some serious communication help is needed before anything can move forward.