New York City. Melvin Udall, a cranky, bigoted, obsessive-compulsive writer, finds his life turned upside down when neighboring gay artist Simon is hospitalized and his dog is entrusted to Melvin. In addition, Carol, the only waitress who will tolerate him, must leave work to care for her sick son, making it impossible for Melvin to eat breakfast.
When bisexual porn star Valentino meets new-in-town hustler Gary, there is an immediate attraction between the two. Valentino helps get Gary a job at a phone-sex company, and they become fast friends and lovers, but tension threatens their relationship when Gary and Valentino's friend Mary becomes involved. When Valentino finds out he is dying and Mary is going to have his child, the three must work through hard times together.