Green’s Dictionary of Slang

(US) cunnilingus.

1964		‘R. Blake’ Amer. Dict. Sexual Terms 26: bush dinner (Vulg Sl) A performance of oral intercourse on the female; cunnilingus [Simes:DLSS].
1966		Trimble 5000 Adult Sex Words and Phrases.
1972		B. Rodgers Queens’ Vernacular 139: The vagina when erotically licked. [...] bush dinner.