I don’t know why this is a guilt because I don’t feel it’s wrong given the circumstances however I need clarification please

When I was a younger child (I don’t even remember how old I was, must’ve been between 10-13). My family were good friends with our neighbours who had kids too. My sister and I would join our parents when they would spend evenings together and mix with their kids.

My sister and I have a 7 year age gap and I think their oldest son was a year or two older than her. My sister had a crush on him and he had an obvious crush on me however, I suppose at the time, an age gap didn’t really cross my mind, we were all friends and always hung out.

One evening the son and myself ended up alone and in the situation in which he was standing facing me and somehow was stroking and light kissing my abdomen area (nothing s***** or anything more occurred). Sounds bizarre I know but yeah, I think it happened maybe one more time after that.

Anyway, a year or so later our families grew apart and we ended up no longer speaking for several reasons; however, as of recently my sister has got back in touch with the kids and it has brought back those memories that took place when we were children however I am now 20 and I feel he may still be considered to be a child by about a year. Does that matter?

Of course I would never repeat such a situation now, I’m in a serious relationship also but I just can’t help feel like I have done wrong even though as i type this I feel like i’m super overthinking

Comments would be appreciated xx