On a recent Tuesday afternoon, Mindy Weston scrawled a message on a whiteboard in a library here at Brigham Young University: "Sex without marriage = bad." That’s the entirety of what young Mormons are taught about sex, she said. At 18, that was all she knew. Then, just weeks before she was supposed to start her first semester as a BYU undergraduate, she was drugged and raped. "I didn’t tell anybody for years," said Ms. Weston, who is now a 41-year-old graduate student in mass communications at the university. "I knew that I would be judged. I knew that I would be blamed. And I knew the story would be twisted."