one year my mom made homemade fruitcakes. a proper fruitcake recipe calls for the cake to be soaked in rum or whiskey for about 6 weeks. she took the cakes and gave them to my grannies on christmas eve. they bragged on them profusely.
the next day my granny brennan called and chewed my mom's ass out because she was a christian woman and did not drink. of course my mom apologized. it was a legitimate mistake and she just didn't think about the fact that soaking the fruitcakes in liqueur would violate my grannies' religious beliefs.
mommy then called her mom and apologized for the fruitcake. this granny told her that it was alright and she understood. she also confessed that it was the best fruitcake she ever ate!