John is a sad sack. Big and fleshy, a nice guy, but as played by John C. Reilly, kind of lost. Oh, he has excuses: He’s still smarting from his divorce — seven years ago — and can’t believe his ex has moved on. Still, even he thinks he should be able to put up a better front. Drunk at a party he’s been dragged to, he’s getting shot down so often by the women he’s attempting to pick up that after a while he barely even tries to make conversation.
Enter Molly, played by Marisa Tomei; with her, he’s got chemistry. She goes home with John — starts seeing him regularly even. But no matter how intimate they become, she always slips out of his apartment before dawn, and she never invites John to her place. Finally he goes over anyway to snoop, and gets a surprise: She’s got a son, a chubby, clingy 21-year-old named Cyrus. Molly’s neglected to mention him, possibly because their relationship is so close that there’s not much room for anyone else.
John quickly senses a passive-aggressive edge to Cyrus’ apparent friendliness, and before long they’re locked in a ferocious competition for Molly’s affection — always pretending, of course, that they’re best of buddies when she’s around.
Now, it’s easy to see how this could turn coarse and conventional in the wrong hands. Jonah Hill, who plays Cyrus, has mostly turned up before in slapsticky commercial comedies — Superbad, Forgetting Sarah Marshall, Get Him to the Greek and such. This, happily, isn’t one, and he’s dialed his personality way back. What’s left is sort of a bottled-up menace that audiences will very likely find nearly as unsettling as his rival does.
