The Scouting Book for Boys (2010)

Thomas Turgoose (This Is England) stars as David, a young boy who lives a carefree life on a coastal caravan park with his best friend Emily (Holliday Grainger). When David learns that Emily is being forced to move away, he helps her hide out in a remote cave on the beach. But as David watches the police close in on his missing friend, their innocent secret takes on a life of its own. When the real reason Emily wants to escape comes to light, David's world is shattered. Swept up in a situation out of his control, and with his feelings for his best friend growing stranger by the day, David is forced to take action.

Source: TMDb