NS (pee) or GS (Golden Shower) refers to the use of urine in sexual services - as a fetish practice. A distinction is made between “NS active” (the sex worker urinates) and “NS passive” (the customer urinates on the sex worker or vice versa). Usually only over/on the body, not mucous membranes.
Health risk low with intact skin. For the sex worker there is often an additional charge; Hydration necessary before appointment.