Amiable slacker David Wozniak (Vince Vaughn) drives a delivery truck for his family's company and is content with a life of mediocrity. However, when he learns that he is the biological father of more than 500 offspring and many of them are suing to learn his identity, he decides to hold himself accountable for his actions. He finds some of his progeny and becomes involved in their lives; however, when David's girlfriend announces her pregnancy, she keeps her expectations low.

David has the shock of his life when he finds that his sperm has been used to father more than 500 offsprings. He tries to remain in the shadows but curiosity gets the best of him and he begins to learn about these amazing children. It's sweet to see his parternal instincts quick in. He rallies everyone together to build an extended family. It's touching to see how doesn't abandon one particular child who has severe medical issues. The ending is heartwarming.