idk what to do about this....

He knows I don't like. She spam texts Hun if he doesn't answer late at night or even during the day. He trash talks to a lot to her ( read there convo a few times) he says things about how annoying I am and that he wishes he could just leave me and when ever we have an argument he seems to tell her everything and even lie about me to her. He told me that she's annoying and the she o my texts him but last weekend she snapped him and it made me in a bad mood and he said she sent it to everyone ( when she didn't I know for sure) and she was piss drunk. He lied about going me seeing her before and idk what to do about it when ever I see her name on his phone it pisses me off and it really hurts my feeling. Idk what to do about it. These are a few screenshots of there convos. Grey is here green is my boyfriend