I have read about rectal probe electroejaculation all over the place, but have never been able to find a video of a human having it done. There are several videos of bulls having it done, but it looks fairly brutal. I understand it requires anasthesia unless the human male has a spinal chord injury that gives him no feeling below the waist. It still sounds like a fascinating thing to watch. I would assume rectal twitching, a growing erection, and a squirt or two of semen.