The Alfred Hitchcock Hour (1962) : 1x31

Dr. Don Reed falls in love with a nightclub singer named Niki Carroll despite the warnings of his seriously ill father and her ex-boyfriend who both tell him she is not good for him. Niki accepts his marriage proposal, but Don's father dies when he hears the news. The newlyweds take an exotic honeymoon cruise with the inheritance money. During the cruise, Don becomes enraged when he sees Niki kissing another man and he accidently pushes him overboard. Niki convinces Don to keep his mouth shut and since no one saw the incident he gets away with murder. Niki eventually grows tired of him. She tells him that she is going to leave him. She also wants all his money or else she will tell the police about the murder. Niki also dumps her band leader boyfriend, but instead of accepting this he strangles her. The police call Don to the scene. He examines his wife's body in the bedroom and discovers that she is still alive.