Green’s Dictionary of Slang

cunt-lapping adj.

[cunt-lapper n. (4)]

(US) of a person, despicable, repellent, disgusting.

Special Instructions to Players prob. hoax doc. ‘issued’ by US baseball authorities single sheet: Such brutal language as ‘You cock-sucking son of a bitch!’ ‘You prick-eating bastard’ ‘You cunt-lapping dog!’ ‘Kiss my ass, you son of a bitch!’ [...] and many other revolting terms.
[US] letter 28 Jan. in P. Jay Sel. Correspondence of Burke and Cowley (1990) 135: I’m not ashamed to take off my coat anywhere and tell these cunt-lapping Europeans that I’m an American citizen.
[US]W. Guthrie Seeds of Man (1995) 99: Cunt-lappin’ gold.
[US]D. Goines Street Players 163: You cunt-lapping bastard, you.
[US](con. 1964–8) J. Ellroy Cold Six Thousand 95: That cunt-lapping homo Bobby F-for-Faggot.