My Girlfriend is Breaking Up with her Girlfriend, Help me
So I'm very new to polyamory. I am in a relationship with a woman who was already in a relationship with another woman for three years. We fell in love while the other partner was studying abroad (red flag maybe?), but everything was discussed every step of the way. They were already open about being polyamorous, so after some open communication, my girlfriend made it clear she wanted to consider us as two equal partners. The other partner and I are good friends, spend lots of time together, including one night a week both sleeping at our girlfriend's house.
My girlfriend recently told me she is considering leaving the other woman. She says she doesn't think they'd be together if my presense had not reminded the other woman that she wanted to stay with her, and that she is finding that she needs me more often than her. I've tried to help her consider the possibility that she is just reacting to new relationship energy, that whatever minor things are weak in their relationship are just shining too brightly in me, or something like that. I love her, and I want to be with her, but I don't want to advise her to leave the other woman, that feels dishonest and biased. I want her to be happy, and can't advise her. I'm afraid that if I do, and she leaves her, then down the road, I'll be the one resented as the homewrecker.
Someone please help, everyone else I know has no basis of comparison.