Hi, when I was younger I had a habit of constantly feeling up my testicles. Basically I would do it and not even know I was doing it, and be told to stop by my parents. I hear that for women sleeping with their bra on can cause future breast cancer, and I was wondering if constantly touching the testicles and sometimes aggressivly could cause problems in the future. Please share your thoughts.
Here's some information on testicular cancer, including prevention:
Breast cancer and sleeping with a bra - sounds like an urban myth. Sleeping with a bra may cause abrasions [scrapes] and some minor skin irritation - but cancer, don't think so.
Your parents may just have wanted to make sure you wouldn't touch your privates in public - so they told you to stop the behaviour entirely. Young children can't always draw the line between acceptable or unacceptable public behaviour. [They probably discouraged you from picking your nose - same idea.]