Green’s Dictionary of Slang

moustache n.

also mustache
(US)

1. a man with a moustache.

[US]D. Runyon ‘Social Error’ in Runyon on Broadway (1954) 454: Sitting in a chair with a lot of little moustaches around her.

2. oral copulation, cunnilingus.

[US]A.J. Pollock Und. Speaks n.p.: Mustache, sodomy (prison).
[US]Guild Dict. Homosexual Terms 31: mustache (n.): Sodomy, according to Pollock; surely the counterpart of the heterosexual colloquialism of having a mustache for cunnilinctus. A secondary association would be to rim (q.v.).

3. the pubic hair.

[US] in Randolph & Legman Ozark Folksongs and Folklore (1992) I 181: I’ve got a girl in Kansas City, / She’s got a gumboil on her titty; / She can sing and she can dance, / And she’s got a mustache in her pants.
[US]Trimble 5000 Adult Sex Words and Phrases.
[US]Maledicta VI:1+2 (Summer/Winter) 131: Pubes […] moustache, rug, short and curlies and short hairs, velvet, wig, wool.

In compounds

moustache Pete (n.) (also mustache, mustache Pete)

1. an original Italian immigrant to New York, typified by his heavy moustache; thus ext. to describe women.

[US]D. Runyon ‘Too Much Pep’ in Runyon on Broadway (1954) 631: Among them are quite a lot of Moustache Petes, who are old-time Italians.
[US](con. 1960s) R. Price Wanderers 142: That stupid blonde twat thinks Mom’s some kinda Mustache Pete and’ll contaminate her kids.
[US]C. Stroud Close Pursuit (1988) 135: These Gypsies hit three old moustache petes and a widow on Hester Street.

2. an original member of the US Mafia.

[US]E. Torres Carlito’s Way 101: The two old guys [...] Mustache Petes — had the shirt buttoned to the top but no tie.
[US]R. Campbell In La-La Land We Trust (1999) 14: The old struggle between the mustaches and the young turks came about over pushing hard drugs.
[US](con. 1970s) J. Pistone Donnie Brasco (2006) 134: No real wiseguys wear mustaches [...] except some of the old mustache petes.
[US]N. Green Angel of Montague Street (2004) 149: The Mustache Petes [...] ran the game, back then. Old bastards off the boat from Sicily.
[US]C. Stella Charlie Opera 126: Lano’s a mustache to these kids [...] They’re purging all the old mobsters.
[US]Codella and Bennett Alphaville (2011) 18: Unlike his ‘mustache Pete’ first-generation gangster peers, Joe [Masseria] wanted more than just a piece of the [...] rackets.
moustache ride (n.) (also mustache ride) [SE moustache + ride n. (1a)/SE ride]

(US) an act of cunnilingus, from the perspective of a woman.

[US] in P. Dickson Slang!
Jamie Consolation Champs Archive 4 Sept. 🌐 I’m sure any smart female would prefer a ‘moustache ride’ to a Vibrating Harry Potter broomstick.

In phrases

have a moustache (v.)

to perform cunnilingus.

[US]G. Legman ‘Lang. of Homosexuality’ Appendix VII in Henry Sex Variants.