Growing up with siblings can provide someone with either the closest friends or the worst enemies they'll ever have in life. After sharing years of an upbringing, home, and childhood, few other people will know you so well. But that doesn't mean they know everything - siblings share secrets as well as they keep them. Here are some of the biggest (and darkest) secrets people have kept from their siblings. More than little white lies, what these people are hiding might even have the potential to rip a family apart.