Just destroy the Bible in front of them and be done with religion. Check out all the failed prophecies and contradictions, better still show your cousin and boyfriend a picture of the great pyramid.
Not only is the great pyramid the object Russell measured to show he was right about Armageddon coming in 1914 but it was also built before Noah's flood was to have happen. Many pyramids were built before the flood and none show water damage many buildings, Mastabas and grave sites made before the flood in Egypt show no sign of flood damage. Icecore samples from Greenland and the Southpole going back 800,000 years show no sign of a world wide flood 4400 years ago.