Green’s Dictionary of Slang

to fight, esp. in the context of a lover’s tiff.

1809		E.A. Kendall Travels III 292: The women had not much to say in politics, though now and then they would spat up [DA].
1848		Bartlett Dict. Americanisms.
1885		F.C. Baylor On Both Sides 345: ‘The American ladies spat on all occasions, [...] I have read,’ [...] ‘We don’t quarrel any more than any one else,’ said Bijou, quite misunderstanding [DA].
1896		P.L. Dunbar ‘The Rivals’ in Lyrics of Lowly Life 61: ’Twas me an’ Zekel Johnson; Zeke / ’N’ me’d be’n spattin’ ’bout a week.
1957		H. Simmons Corner Boy 192: I saw your guy [...] he looked kind of peeved. You all been spatting again?
1977		G. Swarthout Melodeon 25: ‘Oh, we spat,’ he said [...] ‘Don’t your ma and pa go at it now and again?’.
1999		Indep. on Sun. Culture 5 Sept. 4: We spat a little when he went through my prints.
2015		L. McInerney Glorious Heresies 226: ‘Ryan, honestly, if you’re going to spend any more of tonight spatting with clowns...’.