So ein Schlamassel (2010)

Jil has found great love in the landscape architect Marc. There is only a tiny problem: Marc is not a Jew, and Jil's devout Jewish family would never accept marrying a "goi," a non-Jew. There is only one thing that helps: Marc, son of a German bourgeois family, must pretend that he is also a Jew. After a quick course in terms of traditions and customs, this also seems to work quite well. Jil's family is thrilled with the new friend. But then the dizziness flies up just during a big bar mitzvah celebration - and Jil has to decide.