I really don't have much in the way of advice for you, except to tell her you love her and let her know you want her to stay. She's her own person and she'll do what she feels is best for her, and regardless of what you want you can't really change that. She may be letting NRE get the better of her (if they have only been seeing each other for a short time, she may be thinking the grass is greener on the other side. It very seldom is). There is always the possibility that she is not really poly and is using it as a way out. If she does, then I'm guessing she's really not poly after all. If she really wants to leave then sadly there's not much to be done about it. The only thing I can think to say is that if you love her, let her go. If she comes back to you, then you know it was meant to be. This is such a hard thing, and my heart goes out to you. Don't lose hope, though. This may be building up her other relationship to be more than it is. Sometimes people have to try something to realize the grass isn't always greener on the other side. I wish you the best and I hope things work out for you. If you need to talk, there are lots of great people here.
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