"Girls, get those balls out of your shirts. You are not old enough to have boobies yet."
"Please stop pretending that you are a mosquito and poking me with that pipe cleaner."
"If you don't want your sister to bite you, then stop putting your finger in her mouth."
"If you don't want your brother to pull your hair, then stop putting your hair inside his hand."
"You may only give your sister a wedgie if she won't stop bothering you...don't just do it for fun." (I was only kidding when I said that one...kind of.)
"Get your funky feet off your brother. You're going to give him ringworm."
"You don't have to announce it to the world every time you have to poop."
And my all-time favorite...probably because I wasn't the one who said it:
Jay: "Abby, what you are doing right now makes me want to pull out all of your hair and weave it into an Indian blanket."
Abby: "Awww, you're just joking, dad."
Jay: "Yeah, you're right. I would never make an Indian blanket."