Green’s Dictionary of Slang

cocksucking n.

[cocksucker n. (1)]

(orig. US) (performing) oral sex.

[UK]‘Walter’ My Secret Life (1966) III 474: I did not like either cock-sucking or cunt-licking at that epoch, and stopped Kitty who was bent on stiffening it with her mouth.
[US] ‘Cary Grant in “Who’s a Fairy?”’ [comic strip] in B. Adelman Tijuana Bibles (1997) 101: If there’s any cocksucking to be done Franciska you can do it.
[US]‘Swasarnt Nerf’ Gaedicker’s Sodom-on-the-Hudson 23: There taketh place an ample amount of cruising, groping and downright cocksucking.
[US]L. Bruce Essential Lenny Bruce 301: I learned five minutes of geography and ten minutes of cocksucking.
[US]L.K. Truscott IV Dress Gray (1979) 471: The butt-fucking and cock-sucking that went on.
[US](con. 1940s) C. Bram Hold Tight (1990) 189: Navy kicked you out for cocksucking.
[US]R. Price Clockers 180: Some illegal tableau, from professional cocksucking to crack smoking.
[US]Sandmann ‘Burning Down the House’ Planet Sex Stories [Internet] He was speechless, so I moved up and started kissing and licking his black cuntbuster up and down its length. I enjoy cocksucking so much that sometimes I work myself into an orgasm without any pussy stimulation.
[US]J. Dicker Harry Quebert Affair (2015) 27: Cock sucking, blow jobs, giving head, playing the skin flute [...] America is a pecker paradise.