Noah (Jonah Hill) is a college student who has been suspended and now lives with his mom. After having a disagreement with his mother, he's lured into taking a babysitting job caring for the unruly kids of Mrs. Pedulla: the sexually confused Slater (Max Records), no-nonsense wild child Blithe (Landry Bender) and the pyromaniac adopted son Rodrigo (Kevin Hernandez).
Soon Noah is invited to a party to have sex with his supposed girlfriend (Ari Graynor) who uses him only to get oral sex, she agrees to have sex with him if he brings her drugs to the party. Noah, tempted by the offer, steals Mrs. Pedulla's car and takes the kids to the city, where he meets Karl (Sam Rockwell) in his body building shop. Karl likes to hide his cocaine in expensive baby...