Young Adult (2011)

Mavis Gary (Charlize Theron) is a successful writer of teen literature who returns to her hometown with a dual mission: to relive her glory days, and steal away her now-married high-school sweetheart (Patrick Wilson). However, her mission does not go exactly to plan, and she finds her homecoming more problematical than she expected. Instead, Mavis forms an unusual bond with a former classmate (Patton Oswalt), who has also found it difficult to move past high school.