freak trick noun a prostitute’s customer who pays for unusual sex US
— Eugene Landy, TheUndergroundDictionary, p. 82, 1971
A scrawny white hooker who had been the victim of a “freak trick”–a customer who gets his kicks from brutally beating his girls–was nursing her wounds. — Xaviera Hollander, TheHappyHooker, p. 4, 1972