I'm looking for a slightly dark and creepy line. I've got Evelyn here who's a therapist and I'm looking for one of her patients. His wife was murdered and he's been seeing Evelyn since it happened to deal with his loss and the frustration over the fact that the case is unsolved. She does her best to keep their relationship professional, but being a young woman and inexperienced her walls fall. They develop some form of friendship, but it doesn't go outside of the office for Evelyn. Perhaps even some flirting, but it isn't much.
After a few months his behavior started to change; he's starting to develop an obsession with her. Seeking her outside of their sessions and even stalking her. It doesn't help that he shows up whenever she's with her husband and even tries to seduce her while he's around. To Evelyn it becomes clear that he's using her as a replacement for his wife and his actions are becoming overbearing.