Ex girlfriend is getting to me😤😤😤😤

I know I have nothing to worry about... but I cant help but be upset... Ok so my bf and I have talked about this. He honestly has done nothing wrong. Anyways it started when we first got together 7 months ago, his ex from 1 1/2 yr ago they dated 7 yrs (I know she was his 1st love ) messaged him wanting to know who was this mystery girl he was talking to (me) he was offshore an we didn't tell anyone we were dating until he came home. She told him she was a great judge of character (haha) and shed hate to have to mess her up if she broke his heart... (ok so she could cheat on him an break his heart an use him but threatens me) anyways he texted her back an said everyone would find out soon enough (mind u I'm 27 an hes 21 she just turned 21) so I try to just brush it off.. about 3 month in she messaged him saying hey, he said what do u want she said I miss our talks... he said I've told u if u have an emergency I'll help but other than that were not friends. (Supposedly her mom is a hoe an didn't treat the girl right raised her to use men) I don't know her personally I'm not judging her) so she went on to say ok fine... couple days later she messaged him on fb saying hi again, so he told her look I have a gf just don't message me anymore... about 6 weeks ago she asked him for money for a ticket he told her hell no then today he posted a picture of us together an she proceeded to comment on it... he's told her over an over an she tried to friend request me ... I know everything is ok between us but I can't Stand her she has even been showing up at his friends house hanging out with his guy friends friend (a chick friend) and she was throwing herself at him too it's just becoming ridiculous to me really I don't know I'm just weird I guess she has bf supposedly getting out of jail but asks mine for ,money... uggghhhh I hate this feeling mainly because she was his first love an he has saved her from an ex beating on her so feel an little responsibility for her safety but I think she is big enough to learn on her own I hate this so much I have no word is between he an I but still in my nerves