Green’s Dictionary of Slang

to cheek someone, to be impudent to; thus smart-assing n.

1968		G. Cuomo Among Thieves 302: He tried to cover up by smart-assing.
1970		E. Tidyman Shaft 109: ‘You can complain to the union,’ he had smartassed Persons.
2001		N. Green Shooting Dr. Jack (2002) 256: He had just been smart-assing, saying Dr. Benjamin instead of Benny.