Definition & Meaning of "ball washer"in English

What is the origin of the term "ball washer" and how is it used?

"Ball washer" is a slang term for someone who performs oral sex on another person's testicles. It likely appeared in late 20th-century English, using a literal metaphor: "balls" for testicles and "washer" to describe the act of oral stimulation. The term is used in informal, sexual, or joking contexts, often among peers or in pornographic or adult conversations. It is vulgar and explicit, context-dependent, and never considered polite or neutral.