Why has Philip come back to her now when he hurt her so terribly before?

Lisi works at a real estate company just outside London. Four years ago, she slept with Philip Caprice, whom she secretly admired, and he heartlessly dumped her the very same night. After years apart, Philip suddenly visits Lisi and tries to reconcile with her, which makes no sense given their bitter history. And Lisi has a secret to keep—Philip is the father of her son!