WHY? What's the difference between your own and someone else's? People have been having oral sex for ever and when that happens you do get a tiny but of urine from another person into your system, not to mention lots of other stuff as well and people don't seem to suffer from that. People kiss all the time and exchange saliva. That's probably more harmful than drinking urine. Urine is highly process and filtered by your body. It actually contains lots of water soluble vitamins. Your saliva is full of germs and old pieces of rotten food stuck between the crevices of your teeth that your tooth brush can't reach. I'm sure if you weighed the health risks of getting someone else's saliva in your mouth against getting someone else's urine in your mouth, the urine wouldn't be nearly as much of a health risk. Despite popular belief, urine is fairly germ free. There are probably 1000's of times more germs in human saliva than in urine.