Girl talking to my boyfriend??

My boyfriend and I have been dating almost 5 months now. We were dating for about 3 months or so when he told me there was this girl who liked him and messaged him a lot. Who he did not like. About 2-3 weeks ago I noticed he was hiding his phone from me. So being concerned I checked it just to see if she was who he was talking to. And infact he was. I only read part of one message because i trust him(not her). She was saying how's she's in love with him. Now I confronted him immediately after I saw this asking why he had been talking to her. He had said he's never been the person to turn someone away. So then I asked to see the messgaes since he was innocent. He deleted them. He then told me he blocked her on all social media but not her number. So I forgave him not to mention he was hiding this from me for a week or two. Not too long after we were hanging out and she ended up calling. He ignored it and we went back to the conversation. Well he ended up asking me who had called and asked me if i wanted him to call her I said no and then asked if he would. He basically said I don't wanna talk to you cause you're a b***h. And that was the end of it. That I know of. But I had gotten her number through this and was gonna say something to her. Should I or what should I do? Sorry this was so long.