Delivery Man (2013)

An affable underachiever finds out he's fathered 533 children through anonymous donations to a fertility clinic 20 years ago. Now he must decide whether or not to come forward when 142 of them file a lawsuit to reveal his identity.
 
Director:  Ken Scott
Writers:  Ken Scott (written for the screen by), Ken Scott (original screenplay "Starbuck") 
Stars:   Vince Vaughn, Chris Pratt, Cobie Smulders