The subtleties of your personal relationships are often lost on your parents. That old flame who you had that ugly break-up with is likely to show up on their list of friends. They are liable to write on the wall of that guy whose girlfriend you stole asking what he's up to these days. Parents are great at thrusting skeletons from your closet no matter how tightly you thought you locked them in there. As you get older and your parents nest empties more and more, this only gets worse. There is nothing you can do to prevent this, so try to end relationships on good terms if you can. Otherwise, a disgruntled ex may use the power of parental Facebook embarrassment against you.
3. Friending Your Ex