My ex-grilfriend wants to move away over 100 miles with our daughter to shack up with an internet fling, wat2d?

Wow. For your girlfriend to leave you under those cirstances, I'm guessing you must have put her through hell. Clearly you should have been better to her. Maybe you can start being nice to her now so she doesn't feel like she needs to run away to start a new life as far away from you as she can manage.