I hate my best friends girlfriend even though she's been in our friendgroup for nearly two years
Is it really because of the girlfriend?
Not particularly, but I almost never wanted to hang out with her. Now they're moving in together and I'll be spending a lot of time with her, I'm not looking forward to that.
I understand you're feelings, but it's nice to try and get along with others when you can. If you don't it could just lead to fights with your friend and her.
I feel like it's best if I cut ties with them right now, or after they move in together.
Your friend would be hurt that you would do that. Why not just wait until only you two can hang together before you make this decision?