Green’s Dictionary of Slang

(orig. US) fellatio; also as adj., performing fellatio.

c.1869		Rosa Fielding (1984) 117: A little preparatory frigging, or some provocative sucking, an opportune exhibition of plump white posteriors, such as your Lordship seemed to appreciate just now.
1929		R. Perryman ‘The Dirty Dozen’ in Oliver Screening the Blues (1968) 240: Your sister loves to fuck and your brother sucks dick, / He’s a suckin’ motherfucker, cocksucker etc.
1941		in G. Legman Limerick (1953) 78: She didn’t mind fucking, / But much preferred sucking.
1979		J. Rechy Rushes (1981) 26: Many of the men here are looking for — he sneers — ‘just plain fuckin and suckin’’.
1984		P. Barker Blow Your House Down 26: All George ever really wanted was sucking [...] he actually disliked cunt.
1995		Letters to Penthouse V 216: Then she gave me a final sucking, draining me dry.
2021		Sun. Sport 4 Feb. 🌐 [eadline] My wife sucked off our neighbour while I clapped for carers.