Should I keep talking to him or not?

I was snapping this guy. He started flirting with me and I started to fall for him. We fell asleep on the phone several times. I felt like I could tell him anything and everything. But then I found out he was calling one of my best friends cute and stuff. When I found out he was saying these things to my friend it felt like someone stabbed me in the heart. He’s the first guy that I’ve ever liked. So I don’t know if I should stop talking to him or not. If you have any advice please share.