So my bf of over a year started getting kind of weird about his phone so one day I just went on it just out of curiosity. He was sitting next to me and we had previously agreed that we can go on each other's phones, but I never had done it before. I went on to the Snapchat app and scrolled down a little through people he had been talking to. There was this girl that I didn't really know very well but I knew that she went to our school and was also a Senior (high school). I slid over on their conversation and found that they had been sending hearts to each other. She also comments sometimes on his instagram posts with hearts, heart eyes, and other comments of the sort. I had asked him about it before and he claimed she was just "an old friend". Then I found this on his phone with her. I was very upset.... am I overreacting? Is it cheating?

**He "didn't know what it was" when I asked him what the hearts were.

** He's seemingly only friends with his ex girlfriends & talks to them often like they're all besties

**The day that the girl and him texted hearts was a day I was in another state for a trip and wasn't around.

What do y'all think?