<human>: Can you condense the text into three sentences or less?

My girlfriend and I have a good relationship except for one thing. My girlfriend believes that it's ok to be friends with ex girlfriends and I do not. An old girlfriend of hers contacted her on Facebook and they've started texting. My gf has been open about it with me and hasn't hid anything that I know of. We had a huge fight the other night about it. I don't think she should have a friendship with her. The fight ended without a anything being resolved and they are still texting. Am I wrong to ask her to stop. Also, just for insight, my gf has been in a relationship before with her last ex and that ex was controlling and wouldn't allow her to have any friends. The controlling ex is not the texting ex.
<bot>: My gf wants to text and be friends with her ex and I'm uncomfortable with it but not sure if I have the right to stop it.