A golden shower is when a person urinates on their partner for sexual pleasure. The act of urinating on someone is most arousing because of the dominant dominant/submissive dynamic it sets up as well as the humiliation it entails. Watching a partner wet themselves or the bed is also popular with people who enjoy water sports. Some people even enjoy drinking their partner's urine.
Golden showers are also known as urolagnia, urophilia, and watersports.