Directed by mumblecore stalwarts Jay and Mark Duplass, Cyrus stars John C. Reilly as John, a middle-aged lonely divorced guy who, as the film opens, gets dragged to a party by his remarried ex-wife (Catherine Keener) -- who remains his best friend. After a few clumsy, drunken passes at a variety of women, John encounters Molly (Marisa Tomei), an attractive single-mom who finds John's social awkwardness appealing. They hit it off, and quickly begin a tender new relationship. Problems soon arise in the form of Cyrus (Jonah Hill), Molly's twentysomething son, who has an off-puttingly close relationship to his mom. Soon the jealous Cyrus sets about trying to break them up, and John must figure out how to deal with this unhinged and unexpected rival.
by Perry Seibert synopsis