What's this Chinese film?

What is this Chinese film (I don't know if it came from China or HongKong) who's about some kind of a obssessive fan of a actress, and by obssessively means sexually. I remember he has a inflatable woman, which he probably uses for his own sexual pleasures or imagining the actress. There was a scene that he raped the actress on her own house in the stairs then after a while, the actress succumbs to her and they do it again (you know what I mean) in a room. After their intercourse, when the guy was leaving, I remember the actress shot the guy in the groin with a shotgun. That's all I remember. And also, I think it's Simon Yam who plays the character of the guy. Please help on determining the title of this movie. Thanks!