I know i'm a little late for my $.02 but i agree with Npage to jmo.
You can polish terd. Its still a terd.
I was in your position at one time to a certain point a few years ago. I was with my ex for 2 year and another we were engaged. One day she ended and the next day she was dated her guy friend of 4 years. I was depressed and blah blah. I got over her after few months. But since then she calls me just to talk to me and tell me how much she misses me and more blah blah. I stuck to my guns and never caved in or fell over anything she was trying. Now after 2 years of her doing this every week she finally got the point and stop calling a couple of months ago. Yes I tell her my mind and kept telling her, “You have better odds at winning the mega jackpot then getting back with me”. I told her that line more than my age.
Anyways to the point, I think she heard about the new girl and also she finally felt like she lost control of you and wants the control over you again. Do like me and stick to the new girl. My new gf and I have been together a year starting last week and both of us are saving up for a new house.
For NVMYCJ situation is very very rare nad I’m happy for them.
I vote for the new girl.
Good luck man