Green’s Dictionary of Slang

1. (orig. US teen/campus) the act of kissing (in cite 2008, as opposed to intercourse).

1962		Scott Sullivan Shortest, Gladdest Years (1963) 153: Oh, I admit to bit of kissyface now and then.
1975		G. Underwood ‘Razorback Sl.’ in AS L:1/2 62: Let’s have a little kissyface.
1981		G.V. Higgins Rat on Fire (1982) 80: Billy hugged her and gave her kissy-face.
2008		D.R. Pollock ‘Honolulu’ in Knockemstiff 188: ‘Look, babe, we ain’t here for no kissy-face. Just bend over and say your prayers’.
[2012		J.J. DeCeglie ‘Death Cannot Be Delegated’ in Crime Factory: Hard Labour [ebook] Looking at herself in that bigarse mirror [...] Making kissy faces to her double].

2. used fig. to describe any intimate meeting, conversation etc.

2003

Wall Street Journal letters 6 Mar. A13/1–2: Remember Mike Wallace’s kissy-face meeting with the Ayatollah years ago, There’s Mr. Wallace, kneeling on a pillow, head to the side, gazing up as Khomeini seriously intoned some sort of nonsense. Mr. Rather must have been moved by that scene, because his visit closely paralleled Mr. Wallace’s.