Jet Rider
A jet rider is someone, most likely of the female population, that uses the jets of a bathtub or hot tub, or others of the sort, to masturbate.
Carl: Yo, I was at the pool the other day and I saw a jet rider.
John: What the hell is a jet rider?
Carl: You know, someone that gets off using the jets
John: What the hell is a jet rider?
Carl: You know, someone that gets off using the jets