How to balance a friendship with my ex with a current relationship?

I have a boyfriend in school who I'm crazy about, but I feel badly for my ex who sees us in the halls all the time. My ex and I were still good friends up until I got a new boyfriend. I cut him out of the picture at that point. I care about both of them, but I don't know how to balance my relationship and friendship without giving either of them the wrong idea.|||just treat ur ex like the friend he is. its not your fault u have a bf. u shouldn't worry about that.