Is Inviting Yourself Wrong?

My question of the day is, Is inviting yourself wrong, and or rude?

Why am I asking this question? Because I have had a recurring problem with my in-laws and this issue.

They are constantly showing up unannounced, their daughter calls here and asks if she can come over and spend the night. Also they have shown up and the daughter will ask to stay in front of my daughter.

I think it is totally rude. I have told them and her before that I don't like it, and to wait until they/she is invited.

Why today? I was at work, my mother in law was watching my kids at my house, when my sister in law showed up un announced. Her daughter proceeds to ask if she can stay, then my daughter ends up calling me at work for permission.

I wanted to reach through the phone and wring her (my sister in law's) neck! Not to mention that I wasn't even home!

My answer was obviously no, and I gave my daughter the information to relay, or I could tell them if she was uncomfortable. Nope, she wanted to be a big girl and tell them herself! Yeah!!!

I told her that I was uncomfortable with her being there when I was not. That was how I left it.

What do you guys think?