Did I cheat on him?

For a variety of reasons, my ex and I ended up living together, we never got back together officially, mainly cause I had trust issues for his past abuse and cheating. I know, moving in together wasn’t the best idea but it happened, we agreed upon just hanging out and enjoying some time together before his trip, a “goodbye thing”. I was very resentful and angry for his past mistakes and one night I went partying with some friends and made out with a guy. My ex told me I cheated on him, I think I did a shitty thing trying to hurt him on purpose but we never got back together so I’m not sure about the cheating. Did I cheat on him?
Did I cheat on him?
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