Green’s Dictionary of Slang

lecherous, amorous.

1604		Marston Malcontent I vi: Nay, he is the rustiest-jawed, the foulest-mouthed knave in railing against our sex.
1673		‘Letter from a Missionary Bawd’ in Carpenter Verse in English from Tudor & Stuart Eng. (2003) 427: Them once, for charity, I thought to take, / But seeming rusty Napps, I turn’d them back.
1683		London Jilt pt 1 24: She [...] continually preached to me that those old Rusty blades who did it only once in four and twenty hours were the best and gave most Money.
1696		Motteux (trans.) Gargantua and Pantagruel (1927) II Bk IV 272: A bawdy bachelor, talking with an old trout was saying, Remember, rusty gun. I will not fail, said she, scourer.
1908		Sun. Times (Perth) 17 May 1/1: The spectacle of the ‘rusty’ old inslinger with 100 nieces is diverting.
1911		Truth (Sydney) 29 Jan. 5/3: I’ve no doubt she loved him awful, / That there rusty feller, shure.
c.1935		‘Esther Williams — Get a Li'l Like the Fishes Do’ in http://tijuanabibles.org 🌐 Maybe when he blows that rusty load it’ll be different.
1966		Trimble 5000 Adult Sex Words and Phrases.
2019		Digga D. ‘No Diet’ 🎵 Got a rusty ting from South with the mouth / [...] / I’ma buss in her mouth by all means.