immediately, only if the other person has an infection. but urine it's high in salts, and if the person lives an unhealthy life, it's bad because the body eliminate the waste (toxins and high amount of whatever you body don't need) through the urine, so it would be concentrated.
i guess if it's just some times, it's not really bad. and if the person is healthy, too.
Idk where people get the occasional idea that urine is sterile, it's NOT. However, it has the same level of risk as kissing and swallowing someone's jizz, which don't get me wrong is high, but clearly not threatening enough for people to not do it. Any exchange of bodily fluids has health risks so it's more like pick ur poison.
Are there no health risks to drinking pee? I get getting splashed, you'll just clean yourself but peeing inside or peeing in mouth seem very risky