Could’ve been unfaithful 😭😭

So we had a night out and we were all wasted. I remember most of the night. On the way home we dropped off 2 guys that we know, and today I was asked by one of the guys mates if I ‘kissed him’ I said no and all he said was ‘ok’ . I would never ever in my right mind do this to my partner although his done it to me. im torn and confused, feeling sick because I don’t know if it happened or not, or why it’s been said for someone else to ask me. I’m not sure if the guy had said it or maybe the 2nd guy thought it happened . I feel so sick to my stomach that my fiancé will hear this and not believe me that I either didn’t do it or can’t remember . Im not sure what to do if I should tell him and we can both find out whether it happened or not OR keep my mouth shut because I’m not even sure if it’s true and we really don’t need any unnecessary drama 😭😭😥🤢🤢🤢🤢