Back in high school, me, some other guys and some girls were having a conversation about how much it actually hurts to get kicked in the nuts.
I started saying something along the lines of: "It doesn't hurt that bad, you all are a bunch of cry babies.", trying to get some girl to bit the bait.
Eventually, it evolves to me saying to one of the girls: "Oh, if you don't believe me why don't you kick me in the nuts really hard."
I continue taunting her, she gives me a half-force kick, afraid to hurt me, I guess. It still hurt considerably but I power through, hoping to get another one. (by this time considerations of how weird this would seem to the others and any fear of my enormous erection being found out were completely overshadowed by my horniness) And so I say to her, laughing: "Is that the best you can do?"
So, she unleashes a vicious kick into my balls that leaves me breathless for a full 10 seconds on the floor and everyone starts laughing.
The pain was giant but my rection was so fucking hard.
Needless to say I jerked off to that moment exclusively for the next week but I was really worried that my social life would be ruined if it was found out that I was a pervert that liked to get my balls kicked by girls. So I tried not to let my horny thoughts get the best of me while in reality land since then.