Which Oscar-winning film was the first Hollywood film to feature a real tongue kiss?

Explanation

Splendor in the Grass is a 1961 romantic drama film that tells a story of sexual repression, love, heartbreak, and manic-depression, which the character Deanie suffers from. Written by William Inge, who won an Oscar for his screenplay, the film was directed by Elia Kazan. It contains Hollywood's first real tongue kiss.