My Girlfriend wants to brings a friend of hers into the situation. She told her about our relationship a few weeks back and it's been a source of tension between me and my Girlfriend since, especially because this friend of Hers has a crush on me and She knows it. I'm worried this could jeapordize what we have, but She says it'll only strengthen it, and that I should try to open my mind a little.

The idea is that the decision is ultimately hers and my input is considered but not necessarily heeded. I understand this, but I'm still worried.