Green’s Dictionary of Slang

1. persuasive, seductive talk.

1890		Kipling ‘The God from the Machine’ in Soldiers Three (1907) 11: I piled up all the sweet talk I’d iver learnt in the bazars on to this she-bullock.
1935		Charleston (WV) Daily Mail 10 May 8/8: It wasn’t any time at all until a hinkty big black man came around in his fancy clothes and began making sweet talk to Ham’s wife.
1945		L. Shelly Hepcats Jive Talk Dict. 35/1: Sweet talk, endearing terms.
1952		W.R. Burnett Little Men, Big World 15: You come messing me up wid your sweet talking.
1959		E. De Roo Go, Man, Go! 109: Tell me the truth or I’ll dent your eyeballs. I discount your sweet-talk.
1961		V.S. Naipaul House For Mr Biswas 88: So I give she a little of the old sweet talk and I see that she was liking me too.
1983		C. Knight We Shall Not Die 10: Dem use sweet talk an’ lies to fool wi.
1992		K. Lette Llama Parlour 102: I’m emotionally diabetic. Sweet talk could give me a goddamned seizure or something.
1997		C. Newland Scholar 201: ‘Save your sweet talk for Sonia,’ he told Sean. ‘You’re gonna need it to speech ’er, now dis is all over.’.

2. attrib. use of sense 1.

1966

J. Mills Panic in Needle Park (1971) 36: Don’t give me that sweet-talk stuff. Where the hell have you been?