Perfect Parents (2006)

After a violent incident in Lucy's public school, her atheist parents Stuart and Alison decide to find her a safe 'traditional' school. The only one they can afford is St. Mary of the Veil, run by nuns whose 'preference' for Catholic families is de facto exclusivity, given the waiting list. So they pose as devout, and get his murky mate Eddie to find them a priest they can 'bribe' for a parish reference, while Lucy is genuinely converted. It works, but when Stuart overhears a dark secret things take a tragic turn.