Since there were some questions I want to explain more about peeing directly into each other. My guy had read about others doing it, it seemed intriguing and so we decided to experiment. We assumed that we could just face and hug while pumping pee into each other. And it actually worked for a short while but as the receiver's bladder started to fill it resisted and even though we tried our best we could not continue and pee leaked out making a mess. (To his credit he cleaned up the mess.) So we gave up for awhile. But my guy designed several longer tubes, one with an enema nozzle on each end, and another that was just a bare tube but very long and smooth on the ends. He also fitted the tube and nozzles to each of us, using tape to enlarge the size to prevent leaks. (My size was larger.) And then we tried again, successfully.
Yes, the problem with me peeing into him was that his enema nozzle only went into the penis but not deep enough to overcome the sphincter resistance. So I could not pee into him unless he allowed it but because my nozzle went all the way into me, he could pee into me and I could not stop him. And that was not fair and equal. But he promised to relax and open his sphincter and so we continued. Also we found out that when the bladder becomes very full, the sphincter opens automatically so that the bladder can empty, and it cannot be kept closed. So I can continue to pee into him and he can no longer resist. However with the other method of using the long plastic tube, each end goes into our respective bladders and our pee flows easily into each other. To prevent going in too deeply the tube is wrapped with tape at a set distance from the end.
Precautions: Drink lots of water prior to play, clean everything completely, pee forcefully prior to insertion to flush any bacteria out of the urethra, and pee frequently after done playing to cleanse the bladder or any bacteria. (which is why one must drink lots of water). Also there is soreness afterward. But we only share pee every few months or so. My other concern, probably unfounded, is that his semen goes into my bladder, when we use the enema nozzle tube, and later, when I pee I am worried that some could possibly enter the vagina. But I have been told that urine destroys semen and also my guy suggested that final peeing could be done through the tube so that nothing would contact the vagina. So I have been doing that, and also peeing back into him at the end and watching him pee for me. I hope this explains all