The Alfred Hitchcock Hour (1962)

S1E31 Run for Doom

Dr. Don Reed finds himself captivated by nightclub singer Niki Carroll, ignoring the warnings from his ailing father and Niki's former boyfriend about her questionable character. When Niki agrees to marry him, tragedy strikes as Don's father passes away upon hearing the news. The newlyweds embark on an extravagant honeymoon cruise funded by the inheritance. However, when Don witnesses Niki kissing another man, he loses his temper and accidentally pushes him overboard. Niki persuades Don to keep quiet, and since no one witnessed the event, he evades justice. Eventually, Niki grows disenchanted with their marriage and threatens to leave him, demanding his money or she will expose the murder. After breaking up with her band leader, Niki faces a violent confrontation with him. Meanwhile, the police summon Don to the scene, where he discovers that Niki is not dead after all.