In the season four episode of The Simpsons "Marge in Chains" Mayor Quimby spoils the twist of The Crying Game. The episode originally aired on May 6, 1993, less than eight months after the movie's release.
From a Simpsons podcast I subscribe to I learned about how Gene Siskel spoiled this same twist when reviewing the movie for Siskel & Ebert's If We Picked the Winners for 1992, shortly after the movie was released. You can watch that episode here. Roger Ebert was none too pleased because he knew the secret was key to enjoying the film.