Weddings can often be occasions of trauma, as well as joy, and so it proves with this ensemble comedy. Well – minus the joy, that is. Adapted with tin ear and cack hands from a French farce, Robert De Niro and Diane Keaton star as divorced parents of adoptive son Ben Barnes. When he gets engaged to Amanda Seyfried (again playing a bride-to-be wrangling parents), he wants his birth mother to be at the nuptials. But she's a devout Catholic, and so De Niro and Keaton must pretend to still be married, despite his having shacked up with Susan Sarandon years back (a grisly early scene involves Keaton interrupting kitchen-table oral sex). Adding insult to injury are a subplot about sibling Topher Grace's unexplained vow of premarital chastity, and Robin Williams as, inevitably, a recovering alcoholic priest.