What would you do.

I was informed by a coworker that my boyfriend had been messaging her friend saying that she looks good now and how are you. I am in his profile picture and his facebook says in a relationship with me. The girl asks what about me and he says that we're not so good right now and that he doesn't want to talk about it. That's all I got from those screenshots but I'm sure she's not the only girl. Please help.