What to do about an ex?

told my boyfriend not to be hanging out with her (she was the manipulative type when they dated and she still treats him like trash) and he changed his mind bc she started threatening to kill herself. well she texted me the other day asking when he was going to pick her up and that shes sick of my unfounded jealousy. well i broke up with him bc he told me he was going to be christmas shopping that day but then i made up with him a day later. last night i saw texts from her asking him if he was going to side with me otherwise she wouldnt be "nice about it like she was the other night" and he said no. I don't know if I should have a talk with him or if I should confront her bc I'm sick of it.