The film takes place over Vivian's spring break (but don't think she is the main character; she and Vince Jr. are totally underexposed). During this time, Vince the father finds his son Tony (Steven Strait) transferred to his prison. He takes him home, not telling him their relationship because Tony stresses that the mother was a "whore" and because Tony says if he ever found his father (who he thinks is dead), he would beat him up (this is because Vince walked out on the family).
While this is going on, Vince is taking acting class (taught by a fictionalized version of Alan Arkin; watch for his monologue on Marlon Brando). Here, due to a terribly cheesy assignment about "sharing your worst secret, Vince meets Molly (Emily Mortimer), a typical thespian (whose mannerisms are way, way over-the-top). In these scenes is where, as my friend said, the script gets "a little flabby."
Literally while this happening (often intercut for dubious effect), class-cutting, literally "too cool for school" Vince Jr. is trying to find porn sites of overweight women. The one he finds (and gets a membership to, which seemed, as my friend said in general about this subplot, a little strange) happens to be operated right behind the family house. Also, we have the dynamics of Joyce and Tony. (They make Vince the father puke at the end.) And, as the Playlist said about Liam Neeson in "Chloe," Vivian is "inconsequential beyond mentioning."
Well, this isn't a great or perfect film. It's actually pretty much a sitcom. But then again, as a friend said, this is one "entertaining" sitcom. It elevates to greatness in the antepenultimate, climactic scene that has a comic moment that makes one recall Bong Joon-Ho's "The Host" and the amazing and hilarious funeral scene, which it unwisely follows with a tack-on, "happy" (as a member of Metacritic said) ending. You could be smitten as many people have been. I was, partially. I never thought it was that bad, but it wasn't great most of the time (as Ebert said of "The Taking of Pelham 123"). B-