Actor-turned-director David Schwimmer's romantic comedy stars SHAUN OF THE DEAD's Simon Pegg as a genial deadbeat who realizes that abandoning his pregnant girlfriend at the altar was the biggest mistake of his life. Slacker Dennis Doyle (Pegg) can't believe how lucky he is that smart, beautiful, ambitious Libby (Thandie Newton) loves him, but gets panicky when she becomes pregnant. Too spineless to talk through his reservations, Dennis stews in his own cowardice until the day of the wedding, then bolts as the family begins walking to the church. Five years later, Libby and Dennis maintain a cautiously cordial relationship for the sake of their son, Jake (Matthew Fenton); for all his failings as a boyfriend, Dennis has taken to fatherhood with genuine enthusiasm. But while Libby runs her own thriving boutique bakery, Libby's Hot Buns, Dennis is barely making ends meet on his salary as a security guard. Actually, he's not making ends meet; he's in perpetual debt to his landlords, chubby Mr. Goshdashtidar and his ferociously fit daughter, Maya (Harish Patel, India de Beaufort). Dennis would like to rekindle his relationship with Libby but doesn't have the nerve to try, and anyway, all her energy is wrapped up in Jake and the business — Libby has no time for romance. That is, until she meets American hedge-fund manager Whit (Hank Azaria), who's disciplined, financially secure, good at following through on promises and conspicuously devoted to her — everything Dennis wasn't. With the prospect of losing Libby to another man staring him in the face, Dennis vows to win her back by proving that he can change his loutish ways. Where better to start than by running the same marathon for which Whit has spent months training? Pegg and Newton do their considerable best, but they're stuck in the kind of broad comedy that insists women who think they deserve better than unkempt, commitment-phobic layabouts who disappoint them constantly need to think again: Men who seem to have it all together are just pretending so they can get chicks. Pegg's rewrite of Michael Ian Black's script adds a dash of English contempt for go-getting Americans, with their prissy aversion to smoking and self-centered gym obsession, but it's still formulaic and thoroughly conventional. The film's bright spot is Irish comedian Dylan Moran, who plays Libby's charmingly dissolute cousin and who also happens to be Dennis' best friend. He's fresh, unpredictable and genuinely funny — everything the film isn't.