His Buddy's Wife (1925)

Jim McMorrow and Bill Mullaney become close friends during the fighting in France, and Bill asks Jim to look after his family if anything should happen to him. Bill does not return from a patrol in no man's land, and Jim goes to the Mullaney farm, taking care of Bill's wife, Mary, and old Mother Mullaney, who dies shortly after Jim arrives. Jim and Mary are left alone on the farm, and the neighbors begin to gossip. Mary decides that she and Jim must be married, but Bill reappears on the eve of the wedding, telling of his capture by the Germans. Jim quickly realizes that Mary still loves Bill and reluctantly passes out of their lives, finding a cup of gall where he expected a wedding feast.