CHEATING???‼️

Would you consider this cheating. So my boyfriend and I have been dating for almost 2/12 years. Well we went on a break ab a year ago and ever since then I can’t move past this situation. During that time I had moved back home but we still continued dating. Everything, going out , hanging out and even having sex. We just wanted some space. We just agreed to seeing and hanging every couple days. Well during this time he was talking to “an old friend”. Well I knew this girl bc we had class together in high school and she’d always talk to numerous guys and always get dumped and play the victim. We were never friends bc I just didn’t see myself liking her. In high school we all worked at McDonald’s lol. That’s how I even met my boyfriend to begin with. She’s always flirted with him and called him handsome ALOT even before me and my boyfriend dated. Well once we started dating she didn’t say as much to me or him. She’d see us at school and only say hi to him when I’m literally standing next to my bf. I thought it was pretty rude but I knew she had liked him and he knew as well. One day at work (in the beginning when we were first dating) my boyfriend asked for some water or something to drink but he was being a jerk that day and I told him to wait and I’ll get to him in a few minutes. Well he wanted me to get it for him now and instead of waiting he asked the girl and she smiled and laughed bc obviously she heard. She then called him handsome. Not as a compliment but more of as a nickname. I didn’t think too much of it back then but he was flattered that she always did this. Well fast forward to the incident. They say i found out was my bday, right after we had sex. I decided to randomly go though his phone because I had never done it and I’m curious. Well I went it and found him talking to her and sliding up on her snaps on Snapchat. He also slide up on one of her basically damn near naked. That’s the one that mostly pissed me off besides the fact that he was talking to her to begin with knowing she liked him. Well I confronted him and he said it’s not a big deal bc they were just talking as friends. In my opinion I don’t think you should even communicate while in a relationship, with someone you (he) was once interested in and same for her liking him and him knowing. He says he never liked her but why would he message her and get excited when she’d talk to him ?? Every time I bring this situation up he laughs and says he didn’t cheat. But I told him I felt as if he did bc he’s willing to talk to her and who knows what else if I hadn’t seen these texts. So would you guys consider this cheating & how should I get my point across to him that it actually did hurt, I thought he’d never act like that.