Our family had relatives visiting so my brother and I ended up sleeping together. I was perhaps 10 and he was 12. I don't know exactly how it happened but at one point I ended up with his penis in my hand.
I then began to move my hand and jack him off. He unloaded onto the sheets and I remember thinking about mom washing those sheets and seeing it.
I don't think I was old enough to be playing with myself as yet & don't know what made me do it.
We never talked about it ever and never did anything again.
Now that about 50 years have elapsed, I would like do this again with someone else.