Movie title search

Please can someone help me find out this movies name? So, there's a couple, where the ladie's bf/husband is talking loudly and a man who know's the couple overhears it. The man's not talking to his companion though, but to someone who's in collaboration with him. The man who overhears it is I think some type of criminal and he goes outside to warn the lady friend that her bf/husband is planning to have her killed. He was in the basement or somewhere discreetly hiding. But after he hears the mans conversation he aborted his criminal endeavor in hopes of saving her. The lady I think ignores his advice, and proceeds into the house. Where her bf, is talking on the telephone. But in what seemed like a hasty panic (bf, wasn't expecting her to show up) abruptly ends the call. But he said the person's name out as if to make it seem he was talking with another woman who was a friend of the couples. And that's the catch, see the woman who he tried to make it seem he was talking with the lady knew was dead. She stumbled upon her lifeless body somewhere else. So as soon as she heard her bf say that name, she knew he was infact up to something malevolent, and that the man was likely telling her the truth. That's the meat and potatoes of it I think. It was just such a strange scenario in a movie, I can't help but wonder what movie this was in.