John (John C. John C. Reilly) has been single since he divorced his wife, and the news that his ex-wife is about to get married is like a sharp blade, once again inserted into John's heart, indignant he can not help but attend his ex-wife's wedding party. Unexpectedly, at the party, John met the beautiful and gentle Molly (Marissa Tomei Marisa Tomei), and the two soon fell in love with each other. The good times didn't last long, and the appearance of a man named Cyrus (Jonah Hill Jonah Hill) cast a shadow over the relationship between John and Molly. It turned out that Cyrus was Molly's son, and for the 21-year-old, John, a man who appeared out of thin air, was obviously not welcome. Sandwiched between Molly and Cyrus, John is in a dilemma. Can he succeed in getting Cyrus's approval? What about the relationship between him and Molly?