When I was about 8 and my younger sister was almost 7 she would regularly come sleep with me. She hated being alone. my bed was by the window and since we had no a/c she would sleep with me because the summer breeze from the window cooled the room.
One summer night we were laying in bed talking and she asked to see my ‘thing’ as she called it. She said she would show me hers So I agreed. We took off our pajamas and she looked and touched me for a few minutes. Then she wanted to ‘touch’ them together so she put her leg over me while I held my ‘thing’ and rubbed it against her pussy.
I never told anyone about that experience