Breaking the 'Laws'

A disturbing thought came to me the other day. (As if any other kind comes to me, right?) But anyway, it has to do with the concept of in-laws.

When you get married, your husband's parents become your in-laws, right? You are encouraged to call them "mom" and "dad," and hubby's siblings also become YOUR de facto siblings. You treat your husband's family as if they're your family, and vice versa.

That is so messed up, because essentially you are becoming your husband's sister. No, seriously...hey, where are you going? Come back here and hear this out! I'm serious. Where did this practice come from? Why is it socially acceptable to become your MIL's and FIL's next child, thereby making you somehow related to other people in their family in ways that were popularized only in the South? (Us having more teeth, however, and wearing actual shirts with overalls.)

Am I the only one who has thought about this? I mean, of course I will someday also have in-laws and carry on this odd tradition, because that's just how things are done, but I really want to know where and how this originated. No kidding, I'm going to look it up. I hope I don't find out some freaky thing, like we're all related or something. That is another creepy thought in itself. Because I really don't want to think about how that involves people like Richard Simmons.

Word.