Bristol Palin and Levi Johnston have called off their second engagement after he told her he may have fathered a baby with another girl. The other girl was not identified, but a pregnant ex-girlfriend of Johnston has publicly denied he is the father. Palin, the 19-year-old daughter of former Alaska Governor Sarah Palin, told People magazine that Johnston told her about the baby on July 14, the day the couple had announced their engagement. Bristol Palin and Johnston have a toddler son together, Tripp. Palin said the “final straw’’ was when Johnston told her he was going to Hollywood to see a hunting show, but actually went there to star in a music video mocking her family. Palin had said that she didn’t have her mother’s full support over reconnecting with Johnston, 20.