Am I overreacting?

So here's the thing. A few months ago, I started talking to a guy friend again because we had lost contact but now we talk like any other friends would. My boyfriend doesn't like him and I respect his opinion. However, he ended up saying something along the lines of "why are you talking to him" or whatever. Now, here's MY problem. He has a friend and an ex who HE TALKS TO regularly as well. I can't stand it when I see him check his phone and go "oh, it was *name of the girl*". I have never met them because I have NO INTEREST in meeting them, it just infuriates me whenever I see their names pop up in my boyfriend's screen or anything. Am I being too jealous?