Uhm so my story is kinda strange, but I was 6. Every Friday I would go over to my neighbor's house with my mom. My mom and his mom would drink and talk while my friend(he was only like 4 maybe 5..) and I would play together. And we'd do silly truth or dare things and one day we decided to go into the bathroom and rub his penis against this weird chain-saw toy thing.
I don't know why.. I was a disturbed child. But that was the first and only penis I ever saw (excluding porn).