May

May Dove Canady is an awkward, lonely young woman, who suffered from a rough childhood due to her lazy eye. She has very few social interactions, her only "true friend" being a glass-encased doll named Suzie made by her mother and given to May for her birthday with the adage "If you can't find a friend, make one." May works at a veterinary hospital, assisting with surgeries. Her optometrist fixes May's lazy eye, first with glasses, then with a special form of contact lens. As May attempts to be more social, she becomes friends with Adam, a local mechanic. She has a fixation on his hands, which she considers to be the most attractive part of him, and they start dating. Meanwhile, May's lesbian colleague Polly begins to flirt with May. One day while feeling especially low, May remarks that Polly has a beautiful neck. They become friends and Polly gives her pet cat Lupe to May, ostensibly because of her "bitch" landlord.
One night May invites Adam to her apartment. Adam shows her a film he made for his university titled Jack and Jill. The film reveals a story of two young lovers who go on a picnic and end up eating each other. May becomes aroused by the cannibalism in the film. During an intense make-out session, she bites Adam on the lip and it bleeds profusely. Disturbed by May's strange behavior, Adam abruptly leaves. May shouts at Suzie and shoves her in the cupboard.
May begins volunteering at a school for blind children. May gives in to Polly's wishes and starts a short affair. Adam stops calling her and May goes to his house, where she overhears him say that he's glad he could get rid of May. Heartbroken, May visits Polly, and finds her with another girl named Ambrosia. May returns home, miserable. When Lupe refuses to come near her, May becomes enraged. She throws a clay ashtray at Lupe, killing her. May becomes delusional and believes that Suzie is talking to her through the glass case.
May takes Suzie to school and tells the blind children that Suzie is her best friend. The children struggle to take the doll out of the glass case, and the case falls and shatters. May and the children are cut by the broken glass. Scooping up the ruined, blood-stained doll, May returns home devastated.
The following day, May meets a punk boy named Blank. He asks her if she wants to get some candy with him and she accepts. They go to her house afterward. May doesn't like him, but she likes the tattoo on his arm. When he opens the freezer to get ice, he finds the cat's corpse wrapped in plastic. He calls May a freak; she stabs him in the head with a pair of scissors.
On Halloween night, May dresses in a homemade costume resembling Suzie and goes to Polly's house. She slits Polly's throat with scalpels from the animal hospital. When Ambrosia arrives, May admires her legs and stabs Ambrosia in the sides of the head with the scalpels. May goes to Adam's house and finds him with a new girlfriend, Hoop. May kills them both.
At home, May designs her "new friend", Amy (an anagram of her own name), a life-sized patchwork doll made from Blank's arms, Polly's neck, Adam's hands, Ambrosia's legs, and Hoop's ears. She uses Lupe's fur for the hair. The head and torso are scraps of fabric stitched together and stuffed. May realizes that Amy has no eyes and can't "see" her, so May gouges out her lazy eye with the scissors, fatally injuring herself in the process. Crying in pain and bleeding, she puts her eye on Amy's head and begs the doll to look at her. She collapses dead on the bed beside the doll and caresses it. Her creation comes to life and brushes her face affectionately with Adam's hands.

Question: Who gives in to Polly's wishes and starts a short affair?
Answer: May