When I was younger my brother would ask to kiss me. It started out simple and harmless. He wanted "practice" for the future. I'm younger than him and I looked up to him so I thought it was OK. Than it progressed.
I wish my parents caught on to how excited he was to see me naked. How often he would talk about my parts. How we'd slap each others bums as a joke. I remember knowing what he really wanted, but nobody else understood.

I tried to stop his behavior. I'd explain the way I felt to my parents. Beg him to stop. Put up walls and eventually, cut off most intimacy. It wasn't enough, he was persistent. Nobody asked him to stop or explained why it was wrong.

Next, I was older. old enough to know. I guess the circumstance made it feel ok. I thought it would be funny to whisper ASMR into my brothers ear. He didn't react the way I expected, he liked it. So I continued, I felt wanted or loved. I licked his ear and neck all while whispering. I new it turned him on. It turned me on too. We want as far as calling the licking "sex".

And now, the final instance. I was probably 13 or 14. The power went out so I was just chatting with my brother. (To be completely honest I've tried to forget this memory so the details aren't accurate.) The conversations somehow led to me licking his neck again. The air got thick and uncomfortable. I knew I took it to far. We sat in silence for a few seconds before he asked to ouch my clit. In response, I just played dumb and asked what a clit was. The the power came back on just a moment later.