<human>: Can you summarize the given text in a few sentences?

I'm gonna try to make this as brief and to the point as possible. My boyfriend and I started dating late September/early October of last year. All things have been going great - we never get sick of each other even though we see each other at least every other day. In November, we were both watching a movie and he kept texting a girl even though he had his arm around me. His phone was right in front of my face so I could read the convo. I asked him to put his phone up because I was trying to watch the movie and he said "oh sorry, I'm giving this girl advice about this guy she found on tinder. She's bat shit crazy". The first thing that popped up in my head was "well if she's crazy, why are you talking to her?". I got over it and life moved on. 

Shortly after that, we were laying in bed and he dawned on me that that was the girl he had been talking to that night AND the girl he had a picture of on his phone. I'm going to admit - I did go down her timeline. That's when I saw posts/pics she had from September of last year. He would comment "wow" on a selfie of her and like just about every post. I don't know if they ever dated because he has never mentioned it. I'm just concerned that they may have had something going on while we were dating. He still comments on and likes her posts to this day. It's one thing if he has girl friends, but another if he is still talking to an ex. I texted him "hey can I talk to you about something later?" so I will try to bring it up later today. Not sure what I should say/how I should react. 

We get along SO well and always bring things up in a mature way when something bugs one of us. I'm just starting to wonder if things are too good to be true. My last boyfriend cheated on me so maybe I'm just being too paranoid because of that.
<bot>: Boyfriend of 5 months may still be talking to his ex without me knowing about it. Not sure how I should confront him about it.