I think that female ejaculation of lubricating fluid and not urine is possible. However for squirtting fanatics, particularly those who are paying for the service, they are usually receiving urine., very diluted urine. The SP simple takes in an excessive of fluids, usually water and just empties their bladder on command with the accompanying fake orgasm. Another variation of the golden shower, although in a real golden shower the urine is not so diluted. It is as simple as that and that is what they are being paid to do! In my limited personal experience I have had only two woman who squirt small amounts of slightly viscous fluid on orgasm, some others who produced a steady flow which can soak the bed too. and it was not urine. Only once have I had a woman squirt like in a porn video, and she apologized and seemingly admitting it was loss of bladder control in cowgirl. It is impossible for men to urinate with a full erection, and during ejaculation the sperm is protected from urine, which if this was not the case would be incompatible with conception. Woman also in most causes do not urinate on orgasm, again to protect the sperm from urine and to facilitate conception. Maybe in cases of infertility, it could be that a disorder is present which allows urine, either female or male to mix with the sperm or the egg? Nature knows best IMHO