Ex bf May have cheated on me?

So a two years ago I went to prom with a guy who was then my bf. We had been dating for about 2 years we were gonna go alone to take pictures and he told me that he was gonna invite his friend(girl) to come with us and I was cool with it but she also brought a date. So we went and she was being too friendly with me but I was like okay she’s really nice! But the whole time he acted like he was uncomfortable. And she “accidentally” called him babe in the car but I didn’t make anything out of it we just laughed it off. And then as weeks went by he barely talked to me it was more a goodnight text and that’s all and he would tell me how she would visit him at work and she bought him food. But I didn’t make anything out of it since they were “ friends”. We broke up because he just didn’t seem to be interested in the relationship anymore. And now they’re dating what do you ladies think?