My thoughts exactly.
The trouble with 'joeblow' is that for any type of bodily fluid exchange, there better be tests. We don't know if we have anything mild going on inside of us or not, that could be devastating to someone else. Sterile piss? Not likely.
Everyone, take a sample of your piss and look at it under a microscope. See all of those little wiggly things? Take a sample of your piss and properly swab it on a nutrient agar dish and incubate it and see all of those little white dots grow. Didn't even know there was something going on inside, and probably isn't a big deal, just your kidneys doing their job and filtering out the crap, or a few bacteria hanging around the entrance to your urethra.
So please, be as careful of watersports as any STD, but do enjoy the wickedness of it all!
Isn't monogamy grand?