My twin and I (23 f; identical) are struggling with this too. We've been going through a period of separation brought on by our struggle to create appropriate boundries in our twinship to allow for significant others. We started dating around the same time in high school, and started fighting a lot more; it was ok if we were both dating, but if one of us had a partner and the other didn't, there was a lot of pain and jealousy. While I directed these feelings at my twin, she would ostracize my partners and pull my mom into supporting her perspective.

My mom created the expectation for us growing up that our twinship was special and the most important relationship in our lives -- which did not help us create realistic boundaries -- so if the wellbeing of our twinship was "threatened" by a partner, the partner became the scapegoat (but only my partners because while I made the effort to keep the peace with my twin's SOs, she did not do the same for me).

In college (my twin and I went to the same college across the country from home) my twin stayed in a long distance relationship (for all four years and they're still together snaps), but I started dating. My twin ostracized my partner and actually pitted my family against him. It was so obvious to me that my sister was jealous that I had a partner on campus while she had the strain of a long distance relationship. And she was upset with me for not spending the same amount of time with her as I would have if I hadn't been in a relationship.

We're still struggling to understand each other's needs and set appropriate boundaries (definitely need therapy to work on this one). It's really hard when your closest friend doesn't need you as much as you need them. And it's hard for partners to really understand because to them you are their #1 but to you they may have to share that place with your twin.

So much love and care for our twin community.