Green’s Dictionary of Slang

(Irish) to give someone an open-mouthed kiss.

1994		(con. 1970s) G. Byrne Pictures in my Head 66: Outside Trinity, unseeing, uncaring, a couple are wearing. ‘She’s ating yer man,’ says Dave enviously.
2001		G. Coughlan Everyday Eng. and Sl. 🌐 Wear (v) & (n): a very deep heavy kiss, with full tongue action – stuck into somebody so much it’s like you’re wearing them. Common phrase, ‘to wear the head off somebody’ is to give them an extremely long and hard ‘wear.’.