Did i cheat?

TLDR : I had a sexual relationship with someone before + after a relationship, but stayed friends with them and had casual conversation while in the relationship, am i a cheater?

I (18M) am in a relationship with my boyfriend (18M) and we have been together for 9months. I was in a relationship for about a month and a half/two months at the end of 2024 through to the very beginning of 2025 - This is the relationship i have been accused of cheating in, not my current.

My boyfriend had found out that i had sexual conversations with someone, which included photos, around november 2024. I cut things off romantically and sexually with this person about a week prior to getting with my ex partner. Throughout this relationship i didn’t flirt or send anything sexual to that person, but we had casual conversation occasionally - and looking back on the messages i do admit he seemed the slightest bit flirty but i never reciprocated anything. When me and my ex partner broke up, a few weeks after, me and the other person started engaging in sexual conversations again up until march 2025 time.

My current boyfriend has said that i cheated on my ex partner. He told my ex and some of my friends and it has caused a major downward spiral which has caused me to lose friends etc. This all happened about a week ago. I ‘admitted’ to cheating and me and my boyfriend have continued our relationship even though i can tell he is still angry/upset at me.

I need outside opinions on this because there are people in my life who hate me for it and people who think i didn’t cheat. I’m really torn between this because i’ve always been so anti-cheating. I can acknowledge that i am not the best person, i have done awful things in the past and treated some of my ex relationships terribly. But i need to know, did i cheat?

I might delete this thread once i’ve received enough responses but we’ll see, and any questions i am willing to answer.