Name of movie? saw it 3 or 4 years ago. Jumps back and forth from a yacht to....?

I saw this movie. The story jumps from a yacht with man (could have sworn it was dennis quaid but after searching think im wrong) and his wife and his mistress.....and jumps to a separate story about a double murder where this young woman was brought to a remote place from another country. She was not in love with her husband. Turns out she was in love with her brother who eventually came to visit. Much to her surprise he had brought a fiance. While the men were away the woman murdered her sister and her brothers wife.