Demisexual or not?

So, I’m a demisexual (or I thought I was) and I know what a demi is and all that. But I’m confused now because I just recently kissed a boy (a friend of mine) while I’m dating someone else. Long story short, the two of us were lonely and neither of us could see our S/O so our loneliness got the best of us and after he kissed me the first time I was disgusted and in shock and then it just became a regular thing. I didn’t like it and found it gross af but I didn’t mind it in a way because I wanted attention and someone to care about me. My boyfriend is now trying to tell me that I’m not demisexual because if I was I wouldn’t have let that happen. I’m so confused and upset and don’t know what to think anymore. Can I please have opinions?