Is this cheating??

My bf of the summer left today, he called it a mutual breakup but it wasn't, I wanted to stay with him but he doesn't do long distance ☹️. He said this when I met him. So, rn I'm chilling with my ex and I'm horny, nothing here other than sex. But I'm still talking to my summer bf who left for school and sending him pics... am I cheating? I kind of don't want to do anything because I feel like I'm cheating and I miss him honestly. Im just so hurt.