Deadly seminal build up.
Sometimes when I've been on a date with a girl, or just hanging around with a new girl, my testicles will ache. Really, I don't know exactly the source of the pain, it might be further inside, but the ache can even be bad enough to affect how I walk. It happens when I've been around a girl for many hours, usually very early in a friendship when there is plenty of interest, but before there is much sexual fooling around. (It only happens when I'm really attracted to a new girl; it never happens with a girl who I am accustomed to having sex with regularly, no matter how much I like her). It is as if the testes are working overtime, and there can be very noticeable 'seepage.'
The medical authorities who say that this ache is a myth must not have ever been this sexually aroused or they'd know about it first hand.
Anyway, whenever a girl has afflicted me with that ache, I'm seldom able to do anything about it until the date (or whatever) is over. Then, on my way home I look for the first chance of privacy because I have both a nagging horniness and a need for relief from that pain. Sometimes I've been walking home, and able to find a secluded path where I can masturbate. But usually I am driving, and have to find a place to pull over. I can remember several times when I didn't make it very far before having to pull over because I had to jack off bad. I ejaculated a lot of semen then and it comes as such a relief, but for some reason the orgasm is never as pleasurable as normal ones. Have you noticed that, too, you guys? Before long I usually feel like jacking off at least once more.