Explanations/Verbals Thread

This thread is for everyone to share real stories of when a female teacher/friend/anyone else in their life explained to them or someone else anything about a guy's balls being sensitive or a weakspot.

I can only think of one good example of this in my life which was when I was with a couple friends at like a climbing gym, and a very attractive 20 something athletic, blonde, instructor said something to the effect of: Girls don't need to worry about the harnesses too much, but you guys have a lot more moving parts down there. You have to be really careful to attach the harness around your legs otherwise some of those parts are going to get crushed and we all know how sensitive they are. Let's avoid that."

A few of our female friends laughed at that but all of the guys took it to heart and there were no issues. What have your experiences been?