I thought that boys had a bone inside of their penises that would pop out and make them hard. If you stuck something inside the hole and then turned the guy on, it would break the bone and the guy would never get an erection again. This was discussed on the playground as a form of torture.
A childhood belief about rude bits

others believed things like this
- i used to belive when i got an erection that if i bent my penis it would break like a bone— beep41
- i used to believe that a sign in a cafe bone-fide meal meant meat with a bone in it— roy
- I used to believe that my leg has only one bone Anon
- i used to believe that the rag and bone man would come and take me away if i wasn't well behaved— ambrosez
- when you sit by a fire it can dry up you bone marrow— debbie
- When asked why he didn't finish eating the crust from his pizza, a young friend said "I don't eat the bone".— Dustin