This is a very sexy idea that I've tried to find partners for before, but I've always failed.
The concept will take a special partner to pull off, because it's based on some particular kinks (D/s themes, cock worship and frottage).
When a male ejaculates, the "pathway" inside their cock is open for a short time. This is necessary to allow passage of the semen from the testicles out through the tip of the penis.
But what most people don't know is that for that short period of time, men are at their most vulnerable. Because the path through their cock is open, if someone were to somehow cum into the tip of their "open" penis that person could essentially shoot cum right into their victim's balls.
No act is more powerfully dominant than filling a man's balls in this way, and those that are filled find themselves enslaved to the person that did it to them - helpless to the overwhelming pleasure and the feeling of sheer domination.
There is a small underground culture of people who know the technique and who use it to build stables of slaves for their pleasure. But filling a slave isn't a permanant hold - as a males testicles re-fill with their own semen their ability to resist their captor grows.
So to the dominated, freedom is a near goal and their enslavement is a constant process. Some escape, others find different ways of breaking the powerful hold over them.
This is the story of one young college student who gets "filled".
I'd like to brainstorm exactly what the start of the scenario would be, and play it out. And just to be clear - I will be the victim in the story. In the past I've had plenty of volunteers to play the victim, but that's the role I'd like to explore. I'd prefer to play this with a male, but a female partner whos into cock worship and the themes I mentioned above might be able to pull it off.
Anyhow, if it appeals to you I hope you'll send me a PM and we can take it from there. Picking a partner won't be first-come first served, I'll have to be a little picky here :)
Thank you for reading.