I saw this movie long back in sony pix and I don't remember the name . In the movie a man escapes from a place only to be rescued by a couple in an island . This husband and wife have a son and the husband lost his both legs when he was as a soldier .from then he stops having sex with his wife and the wife starts an affair with the man she rescued.that man finally kills her husband .

Eye of the Needle (http://www.imdb.com/title/tt0082351/)