I just talked with GF for the last several hours about how things are now, and everything was good and understood until the sleepover subject came up. It has been a sore subject this whole time, but when we talked this time she decided that she absolutely wasn't happy with that. She handed me the ultimatum.
I reminded her that I had an equal ultimatum from the wife in regards to her not being ok with the sleepovers, so she told me that I should just go home to my wife then because she was no longer going to be in this relationship if I was not going to be spending the night.
I got stuck in between two ultimatums. Wow. That sucked. Poly is difficult.