While I like reading about balls being busted and guys getting raped as part of it...be it by strap-on or by another guy, I have another method of castration I have not seen used yet.
Getting the guy really hard and preparing them like you would for a heavy milking session. Keep them on the edge for some time to make sure plenty of pre-cum is dripping. Then you slowly open their ass up large enough to get a clear shot at their prostate. With all the preparation the prostate should be at maximum size for easy targetting. Then massage the prostate to make them cum hands-free and don't stop after the first time. Work the prostate harder and harder until the muscle walls break down and make them have repeated orgasms as the little gland is being thoroughly damaged by the constant pumping and massaging. Finally, while the massaging is going on, the ass is slowly stretched wider so enough of the hand can fit in and cup the now-battered prostate and squeeze it completely causing all reserves of semen to be pushed out and the small sack structures that held the semen are crushed and internal bleeding is caused and with repeated pumpings of the now destroyed prostate the semen turns to blood.
Net effect is the prostate is dead now and while the testicles still produce hormones and sperm, there is never anyplace for it to go. They will have a sex drive but never can experience ejaculation and possible nerve damage to the prostate would likely eliminate sensation of orgasm. From an outward appearance the victim would look normal but they are effectively unmanned and it would turn what once was the most pleasurable sensations and turns it into pain and destruction.
One storyline I was thinking of would involve high stakes wrestling arena where the contestants were chosen from the audience at random and have to enter the sand filled ring and proceed to wrestle/fight. The winner is the one that fucks and cums in the loser's ass. I was thinking of the final match being against two guys that are heavily hung and are trained in fighting in some fashion. One of them is totally overmatched by the other and is quickly stripped and is being fucked by the apparent winner. The winner is coming from a matial arts class when they came to the matches and was still wear practice clothes and the white clothing was rather baggy, he the loser sees the "winner's" really low hanging heavy balls swinging against the robe and takes a last ditch shot and grabs the guys balls and while the guy is frozen in pain the guy slides off his dick and while still holding on strips him out of his practice clothes and impales him on his monster. The "winner" was close to shooting before this happened so the "loser" pulls the "winner's" shoulders up and spreads him out for the audience to see his low hanging balls swaying free and his dick bouncing up and down while he starts to shoot. The "loser" had already cum once while the "winner" was fucking him so he has a good long time before shooting again. He starts to carefully aim his thrusts in all different directions to break the "winner's" ass open. Then he starts to push the "winner's" ass down to make his legs open a bit wider. This allows him to angle his dick more horizontally forward and put more pressure on his prostate and weaken the muscles there. He makes the "winner" shoot a few more times until he starts to pull his strokes farther and farther out so he can get his dick lined up to hit the pocket that is the guys prostate. He finally feels he hit paydirt and the guy's mouth opens in a "o" as he feels the immense pressure on his prostate and the audience can see the sperm being pumped directly out of him and soon it turns to blood. The true winner now returns to fucking him normally until he shoots and wins.
I have more details of this fictitious arena that adds more spice to it, but I feel this part applied more directly to this board and place.



