Lorelai explains to Rory that Tristan (Chad Michael Murray) called her Mary because of the Virgin Mary, meaning that she looks like a good girl, a virgin. When Rory asks what he would have called her if she’d looked like a slut, Lorelai says jokingly that maybe he would have added a Magdalene to it.
In the New Testament, Mary Magdalene is one of the followers of Jesus Christ, said to have been witness to his crucifixion and resurrection. The Gospels tell us that before she became his follower, Mary Magdalene was healed by Jesus, who drove seven demons out of her. In medieval Christianity she was portrayed as a repentant prostitute, although this is not supported by the Bible.