The Mistress's Revenge

For five years, Sally and Clive have been lost in a passionate affair. Now he has dumped her, to devote himself to his wife and family, and Sally is left in freefall. It starts with a casual stroll past his house, then popping into the brasserie where his son works, then Sally starts following Clive's wife and daughter on Facebook. But that's all right isn't it? I mean, they are perfectly normal things to do. Aren't they?