Grave Decisions (2006)

Original title: Wer früher stirbt ist länger tot

In this black comedy set in small-town Bavaria, 11-year-old Sebastian thinks you can never be too young to be a murderer. He's convinced that he killed his mother on the day he was born and is certain he's already been condemned to purgatory. Deciding he might be able to knock off a few years of his sentence by doing good deeds, Sebastian sets out to find a wife for his father Lorenz. When Lorenz and Sebastian's schoolteacher Veronika fall madly in love with each other, it seems the heavens must be smiling. There's just one hitch: Veronika is married.