A visit to a clinic with a twist...
I wanted to find a story where a patient going into a new futuristic sperm bank. After running some tests on him they find out that his sperm is very potent and they need it. Now the catch here is he will become a "slave" to them without him knowing. They will capture him and force him to orgasm over and over again. That can be achieved through all the stimulation he can get. I have thought the nurse can take him to a certain room that they have a "genetically modified girl".
Outside she will be like a normal human and amazingly beautiful. But she will be much stronger than any man.
Inside her she will be able to control all the muscles of her vagina (tight or loose, pull or push) and inside her uterus,ass and throat will have some containers and a fleshy kinda slimy probe-tube. This flesh-probe tube will slither inside him through his urethra to give him extra stimulation and to suck up all of his juices from the root. While she is doing the "insertion" she can clamp down on his penis so he wouldn't be able to pull out. It will be a pain-pleasure experience for him.
This is the basic idea. I would love a small story around it.!
Thanks a lot in advance!!