my first thought on this was that she is not poly and is trying to take your boyfriend away from you by being the "better" lover. He seems to love this game and all the attention he gets from it. You in the mean time get to feel all the pain, hurt, disrespect, dishonesty, and lack of empathetic communication. Not cool if you ask me. I would so be up one side of him and down the other if he were my boyfriend. I would be reminding him that being humble and respectful is far more attractive for a boyfriend and that he is losing his integrity as a good boyfriend and a person for that matter.
It's all very well for him to be experiencing NRE but that usually includes an ounce of concern and displaced guilt and worry. He seems to have none. I wonder if he is poly in fact of liking the fact that he gets to get it on with two women... I wonder if he really just isn't into you anymore.
Yes, I think it might be time to sit the guy down and have it out. Before you do, it might be wise to come up with some very firm boundaries that you are not willing to budge on until he shows some respect for you and some balanced efforts to make you both feel loved and wanted... I think I would also plan your escape path also. You might find that you will need a place to stay if in fact he really is done in your relationship.
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