Thirty-year old adulteen Vincent babysits animals and children for a living, and his latest job is 9-year old Bart, who just moved into the building with his overworked and single mom. At his new school, Bart is anxious to develop a cool reputation, so when everyone assumes that laid back, eccentric Vincent is his dad, he begs him to play along, especially when his "dad's" fun, immature behavior delights all the kids in his class! Initially reluctant, Vincent changes his mind after falling in love with his "son's" attractive young teacher. And in order to spend as much time with her as possible, he does his best to make sense of the mysterious codes and expectations of his weird new tribe: the Parent-Teacher Association. But Vincent soon faces a bigger issue: How to backtrack on the huge "tiny little lie" he's gotten himself into.