The kiss originated when the first male reptile licked the first female reptile, implying in a subtle, complimentary way that she was as succulent as the small reptile he had for dinner the night before.

F. Scott Fitzgerald (1896-1940) American writer [Francis Scott Key Fitzgerald]
Notebook E “Epigrams, Wisecracks and Jokes,” § 436 (1932-1940)

Originally collected in Edmund Wilson, ed., The Crack-Up (1945), then in the unexpurgated Matthew Bruccoli, ed., Notebooks of F. Scott Fitzgerald (1978).