Scarleteen

I'm curious as to what the possible risks are

The general risk is transmitting infection. Pee is fairly sterile, but not 100% sterile, and it can carry STIs like chlamydia, Gonorrhea, or Hep B (this risk of transmission from urine play seems to be fairly low, but it's still there).

Just to be clear, particularly with people with penises, urine still has to come through the urinary tract, so if any STIs or other infections are present, it can pick them up as it passes through that tract.

this might be an unnecessary question, but does it matter who said urine comes from in terms of non-STI concerns? I mean STIs are a pretty big concern but still