This girl

So my boyfriend and I are both very faithful to each other.well his ex girlfriend keeps texting him like weird stuff like asking if he still has her bathing suit that she left at his house last year!! Then when we first started dating shw followed me on social media and like everyone of my pictures on instagram!!! Then texted after she did it say I've really been missing you wanna come over. He shows me her texts and it makes me so mad! He tells me not to say anything to her because it will just cause drama but she's like really starting to piss me off. Like back of my boyfriend seriously. Am I over reacting!?