I'm 21F and my mind can't stop thinking about this. When I was little, around 4-5 years old, I remember there were several times this happened. And this did not happen to me alone but to two of my sisters. What happened was that my brother would take the three of us into the room and usually at that time our parents were taking a nap.

He would tell me to lie down and do something naughty while my sisters would say "he just wants to clean you up". And what he did to me was pulled down my pants and rubbed his genitals against mine. At that time I didn't understand what was going on, so I just let him even though I weirded out a bit. And then he did it to my sisters too.

This thing happened more than once that it made me remember the weird sensation. From there I started learning to touch myself because I wanted to feel the sensation again. However, when I grew up and understood more things, I thought about it. Is what my brother does child grooming? But he was also a minor back then. I also grew up being hypersexual(?), is it some kind of traumatic response?

I've never talked about this to my sisters because we're all grown up and I feel embarrassed to bring this up again.

(I posted this on the other subreddit first but someone told me about this subreddit so I'm here to share my story.)