The needy teenager Rena Grubb lives with her dysfunctional family of losers in a trailer park. The most popular boy in her school is dating her only for sex, and does not want to be seen with her. Her brother Jay is gay; her older half-sister Barbie is a bitch; and her mother Madge works hard in several low-qualification jobs to raise money to support her family. Rena is asking her mother to go to the annual picnic with her beloved missing low-fife father John Grubb, who is in prison sentenced to two life sentences. Rena is pregnant and collects the cards her father sends to her from the prison. When Madge decides to go with her family to the picnic, and along the day, the family finds how mean and nasty John is, shattering the dreams of Rena with her father...