Obsessive ex-girlfriend

My boyfriend has an ex girlfriend he dated back in high school . After breaking up with her he was with someone else for about 3 years. The new relationship didn't work out and he would talk to his ex when him and his gf were having problems. She was pretty much who he would go to when he was bored and when him and his gf broke up he used her to get over his breakup. This girl never stopped loving him, and my bf made her think that there was a possibility that they could be in a relationship again. After he met me, he completely stopped talking to her. I knew her from high school so when she found out we were talking she immediately started stalking my Facebook and messaged me on Facebook telling me anything she could think of to make me stop talking to him. My boyfriend and I have the best relationship. We started off as friends and after 3 months he asked me to be his gf. We have very good communication and no complaints about each other. The only problem is that this girl continues to message both of us. He already made it clear that he's moved on but she doesn't seem to understand that. She asked me the other day, "How are you and Mark?" She is obsessed. Everything she does with her life is to impress him in hopes of getting him back. She dyed her hair red because that is his favorite color and uploads stuff on Facebook all the time. She recently messaged him to pick up some stuff that she had of him from 6 years ago. WHO THE FUCK WANTS their shit after six years? She is pathetic but was using any excuse to see him. She accidentally liked my tweet while stalking me πŸ˜‚ I'm telling you this bitch is crazy! But anyways.. I don't know what to do. It's been 6 months and he already talked to her to leave us alone multiple times . We both blocked her from all social media recently so hopefully she leaves us alone . Dos anyone have a similar experience? How do you deal with these bitches? πŸ™„πŸ™„