I didn’t get a picture of her doing it, but this is the general idea
My girlfriend is impulsive, which can be very exciting at times. For instance, she thinks nothing of giving me a handjob under the table at a busy restaurant.
One morning, standing naked in front of the toilet she came up behind me as I was peeing. She reached in front of me, and squeezed my penis really hard so the pee couldn’t continue flowing. That fucking hurt! I yelled, and she let go.
Oddly, I’ve masturbated many times remembering that strange incident. Or, she’s masturbated me while I remembered that, and I’d cum way too quickly.
Oh, yes, I told her about it. I told her that although it hurt, and scared me because I thought I could have burst my urethra or something, it sexually excites me to think about it.
So, being who she is, she had to try something. We talked about it for a month, before I finally relented. She was convinced, and finally convinced me, that it wouldn’t hurt me to have her block my penis when I’m ejaculating. Evidently, people have been doing it for thousands of years as a contraceptive method. No one ever died, although undoubtedly many people got pregnant.
On one particularly horny day, we set out to try the experiment. She had me laying on the massage table, and she gave me a happy ending. Just as I hit that orgasmic state, she squeezed the very tip of my penis between her thumb and forefinger.
I instinctively tried not to cum, but of course you know that’s impossible. I felt the pulsing start up, and there was nothing I could do. Even though I had agreed to the experiment, I really, really wanted her to let go. I yelled, but to no avail. I squirmed to get away, but she managed to hang on.
The pulsing became full force, and continued. It kept going, probably for at least twice as long as a regular orgasm. I thought it was going to hurt like hell, but no. Nothing. In fact, it was super-exciting and nice.
The only weird part is that she continued to pinch me closed until my dick went soft. The cum was still trapped in my urethra. And it started to itch inside. I think it must be a chemical reaction. I think semen is alkaline, while urine is acid. The urethral lining is probably used to long exposure to urine, but not so much for semen.
When she let go, the sperm just oozed out.
Overall, it was a great experience.
Now, she wants to try another experiment. She’ll still have to convince me that it’s safe, although I’ll probably relent when I’m particularly horned up. She wants to pinch off the end of my dick again, but then, she wants to push the cum backward, by squeezing back along the length of my penis, and then under my balls until the cum squirts into my bladder. I’m kind of excited about the idea.