Our Ex-Wife (2016)

Jack is keen to make a new life with girlfriend Sara but the wife he divorced five years earlier, Hillary, is still very much in the picture, hate-filled and anxious to see off any new woman in his life. His frustration is increased when Sara naively believes Hillary is keen for his children's welfare and still in love with him - so Jack asks Hillary to dinner, along with his father George and Sara. Hillary and Sara appear to get on but when Sara rings her, offering friendship, Hillary shows her true colours, prompting Jack to take drastic action.