The Simpsons (1989)

S15E17 My Big Fat Geek Wedding

Upon discovering that Skinner is having second thoughts about their wedding, Edna decides to leave him at the altar. After returning one of the wedding gifts, she finds herself in a romantic encounter with Comic Book Guy. Simultaneously, Homer and Marge engage in a heated discussion about the strength of their own marriage and whether it's still as strong as it once was.