Taking Sibling Rivalry to the Next Level

My kids get along 50% of the time and literally fight 50% of the time, so it feels like I am constantly intervening in their issues.  I know I've failed to tell the stories of the funny things they say, and this example might be too complicated to explain/write, but I am going to try my best because this is just a typical example of things that happen multiple times a day.

A few days ago, we were driving to daycare in the morning.  The kids had each packed something to take for breakfast.  Rhett saw me packing leftover pizza for lunch and decided he wanted a piece of pizza.  When Emma woke up, she wanted something with icing (please don't judge), and she settled on a Special K bar (see, it's not that bad).  So, anyway we're in the car, and the conversation goes like this...

Emma: Daddy picking my up today?
Me: Nope, I'm getting you today.
Rhett (at the same time as me in his very bossy and irritated tone):  Emma you say "me" not "my."  You're supposed to say "Daddy picking me up today?"

A few seconds of silence, and I can see in the rearview mirror that Emma is not happy...

Emma: Well, your pizza doesn't have icing Rhett!
Me: Laughing!!!!
Rhett: Crying.
Then me trying to explain to Rhett why this is just funny because why in the world would he want pizza with icing anyway.

This stuff happens so many times a day, it's impossible to keep up with it.

But, here was another good one.  The kids wanted to play dress up.  I thought they were going to get their pirate costumes from last year, but Emma came out with a princess outfit instead and wanted me to help her put it on.  The top was way too short, so her belly was hanging out.  Then, she had plastic high heels, a wand, a skirt, and a crown.  Next thing I know she's trying to stick her wand in the waist band of her skirt (kind of like putting away a sword or holstering a gun), and she says to me "we're going to get the bad guys."  I thought it was pretty cute, since I don't think many princesses in high heels go after bad guys.  Poor girl is just a little confused probably because of her big brother's influence.