Green’s Dictionary of Slang

slob n.2

In phrases

chuck a slob (v.) [slobber n. (4)]

(US gay) to kiss.

[US]B. Rodgers Queens’ Vernacular 46: chuck a slob (obs, teen sl, late ’50s) to kiss ‘Sure I’d let some fag go down on it, but I ain’t chuckin’ no slobs with the cat, man.’.