Ashlee Simpson and Fall Out Boy's Pete Wentz are engaged. “We wanted to be the first to tell you and to hear it straight from us,” the couple wrote in a joint statement posted last night on FriendsorEnemies.com. But despite the public announcement, don’t hold your breath for wedding details. “We consider this to be a very private matter,” the couple wrote. Simpson and Wentz began dating in late 2006, reports MTVNews. (More Ashlee Simpson stories.)