Superman: The Animated Series

Season 2, Episode 18

Episode Title: World's Finest (3)

Air Date: 1997-10-04

Overview:

Lois ends her romance with Bruce Wayne when she discovers that he is Batman. Lex Luthor tries to end his alliance with the Joker, but the Joker turns the tables and kidnaps Lex and steals a powerful aircraft to attack Metropolis.