Hugh Grant plays Will, a 36 year old playboy who has never worked a day in his life. Living off the royalties of his father's one successful record, Will spends his days in the simple pursuit of leisure. Absolved of all responsibilities, he wants nothing more than meaningless sex and decides that the best way to get it is by dating grateful (and needy) divorced, thirty-something women with children. So pretending to have a 2 year old son Will joins a divorcee help group. There he meets Fiona (Collette).
Yet his problems run deeper than merely lying to Fiona about having a child and worrying about how he's going to ditch her when he gets bored. At a picnic, Fiona brings along Marcus (Hoult), a rather strange 12 year old with a manic depressive 'hippy' mother. After she tries to kill herself, Will finds himself visited by Marcus every evening after school and as they grow closer together, they learn about each other and themselves and of course, about life.
This is a very clever feel-good movie that touches on serious topics without being overly sentimental. Will's insatiable sexual appetite and his hedonistic persona force him into increasingly comic moments, but will he discover that when Marcus needs him the most, that he's not perhaps as shallow as he'd like to believe he was?