Green’s Dictionary of Slang

(US) to chatter, to gossip.

1949		‘Josephine Tey’ Brat Farrar 233: [C]ompetitors who had taken part in the sober events were now walking ponies and coffeehousing while they waited for the bending race.
1956		L. Shapiro Sixth of June (1958) 259: These damned coffeehousing gunners. Don’t know a war from a pink tea.