In last week's episode of TLC's "Who Do You Think You Are?" we saw Kelly Clarkson whimper and cry, overwhelmed by pride in her great-great-great-grandfather . Tonight, we come back down to earth, thanks to one of the funniest ladies in Hollywood, Christina Applegate, whose family background serves to remind us that most family backstories are slightly more dysfunctional than Clarkson's. Applegate wears glasses, which might be because crying and reading old documents is hard on contact lenses. She learns that her father was abandoned by his mother when he was just a little boy. Traditionally, many families prefer their skeletons locked in the family closet, but Applegate is bravely sharing her experience, telling omg!, "It's so personal, but it's a good episode, so you'll see. You'll cry a lot." You can't say you weren't warned. And be sure and check back this week for the juicy details. "Who Do You Think You Are?" airs Tuesdays at 9 PM on TLC.