Green’s Dictionary of Slang

boom-boom n.3

(US) sexual intercourse.

[US]T. Southern Blue Movie (1974) 246: Feral no try boom-boom. Just happen. Feral very sorry.
[US] in C. Browne Body Shop 96: Hey, GI, you want my sister, beaucoo boom boom.
[US](con. 1969) M. Herr Dispatches 36: ‘Changee money,’ ‘Boom-boom picture,’ ‘Dinkydau cigarette.’.
[US]M. Baker Nam (1982) 147: Candy, soda, dirty pictures, boom-boom, dope.
[US](con. c.1970) G. Hasford Phantom Blooper 147: One of the Seabees says, ‘Hey, baby-san, you souvenir me one boom-boom?’.
[US](con. 1966) J. Laurence Cat from Hué 400: Page numbah one bird catcher. Never pay for boom-boom.

In derivatives

boomboomer (n.)

the vagina.

[UK]R. Milward Man-Eating Typewriter 56: The spiv (and all those pops before him) jad got closer to my Mre’s meshigena boomboomer than I ever could.

In phrases

boom-boom (girl) (n.)

a prostitute.

[US] Letter in Edelman Dear America (1985) Apr. 49: In pidgin Vietnamese-English [...] handy phrases [...] are: titi – very little; boo koo (a bastardization of beaucoup) – very much; boom boom – whore.
[US](con. 1968) Bunch & Cole Reckoning for Kings (1989) 216: She gets looked at as if she were a boom-boom girl.
[US](con. 1969) N.L. Russell Suicide Charlie 1: The boom-boom girls back at the barter point clutched at their breasts and wailed like mourners at a mass funeral as we loaded onto choppers and lifted skyward.
[US](con. 1966) J. Laurence Cat from Hué 400: More like a boom-boom girl in Cholon.
boom-boom parlor (n.)

a brothel.

(con. 1965-66) P. Caputo Rumor of War 108: Dogpatch [i.e. a bar/shop area near Da Nang air base] has acquired several whorehouses since the brigade landed. Boom-boom houses they are called in the local slang.
[US](con. c.1970) G. Hasford Phantom Blooper 147: This steam-and-cream is the most famous and most popular boom-boom parlor in Eye-Corps because it features only round-eyed whores, none over the age of fifteen.