Does this square with “family values”? In an interview that will air on Monday on The Tyra Banks Show, Levi Johnston says that Sarah Palin allowed him and Bristol to share a bedroom in her home, even though the Alaska Governor probably knew they were having sex. "I'm pretty sure she probably knew," says Johnston. "Moms are pretty smart." Johnston and Bristol called off their engagement last month after their son, Tripp, was born in December. Johnston also says that he and Bristol had safe sex “most of the time,” and that he needed to “mature” before marrying Bristol.