Green’s Dictionary of Slang

dirt road n.

the anus.

1916		H.N. Cary Sl. of Venery IV (t/s) n.p.: (human body) The Anus [...] dirt road.
1949		Monteleone Criminal Sl. (rev. edn).
1966		Trimble 5000 Adult Sex Words and Phrases.
1972		(con. 1930s–40s) B. Rodgers Queens’ Vernacular 108: Hobo slang (kwn ’30s & ’40s) The ass itself became the dirt run, old dirt road and old rip. These words seem to indicate that pederasty was more important than fellation among the homosexual hoboes.
1976		‘Peter Pepper’ Hott Butt Eager 180: ‘Anytime you’re hot for a dong up the ol’ dirt road, sweetie, just come in and crawl between the sheets’ [Simes:DLSS].
1991		in W. Leyland (ed.) Eighteen & Over 36: Like a slut, I leaned over the stack of cardboard boxes and the Mexican rammed his cock up my dirty road [Simes:DLSS].
1997		Cherry Boys (L.A.) Jan. 13/2: Let the fuck begin. I was going to plow the sailor’s dirty road [Simes:DLSS].
2023		(con. 1962) J. Ellroy Enchanters 30: [of a divorcing wife] She’ll get wise and brown him up the dirt road.

In phrases

go up the (old) dirt road (v.) (also go down the dirt road, ...up the dirt route) [fig. use of colloq. dirt road, the highway]

to perform anal intercourse.

c.1930		‘Adventures of a Fuller Brush Man: “The Amorous Mrs. Twirp”’ [comic strip] in B. Adelman Tijuana Bibles (1997) 47: ‘Up the Dirt Route’ Very popular with wolves, Greeks and other perverts.
1939		D. Maurer ‘Prostitutes and Criminal Argots’ in Lang. Und. (1981) 116/2: To go up the dirt road. To practice pederasty.
1941		G. Legman ‘Lang. of Homosexuality’ Appendix VII in Henry Sex Variants.
1965		Guild Dict. Homosexual Terms 12: dirt road, to go up the (old) (v.): To pedicate.
1972		R.A. Wilson Playboy’s Book of Forbidden Words.
1989–2003		R.O. Scott Gay Sl. Dict. 🌐 anal intercourse: [...] Syn: goin’ down the dirt road.
1998		B. Keane ‘Dysfunctional Family Circus’ 🌐 I told you before we came up here, if Dad has too much to drink and wants to go ‘Up the Old Dirt Road’, it isn’t because he has to take a piss!
2002		Sexionary at www.sarahhedley.co.uk 🌐 Go up the old dirt road – anal sex.

take it up the dirt road (v.)

to be sodomized.

193?		B. Adelman Tijuana Bibles (1997) 76: ‘I like mine up the dirt road’.
1957		G. Legman More Limericks 205: There was a young fellow whose mode / Was taking it up the dirt road [Simes:DLSS].
1999–2003		Movie Films Fest ‘Legacy’ Rev. on Excalibur Films 🌐 Wide, hard cocks aren’t a problem for either of these anal sluts as both of them take it up the dirt road with slutty glee.