Sibling rivalry

MADELEINE: happily and quietly playing with her Leapfrog Learning table.
JULIA: Mommy, I want to play on that side, I don't want this side (pointing to the side of the table Madeleine is standing at.)
ME: Well, Julia, this is Madeleine's toy, and she's playing on that side right now. Besides, you already got to play with this twice today, and this is the first time Madeleine is getting a chance to use it.
JULIA: No, I didn't. I didn't play with it.
ME: Yes, you did. You played with it two times.
JULIA: No, I did not!
ME: Okay, whatever you say.
JULIA: Mommy, I wish all Madeleine's toys could be my toys.
ME: Well, you don't like Madeleine to play with your toys, and you get pretty upset when she tries to touch them, so it's not really fair to say you want to be able to touch all of her toys.
JULIA: laying on the floor and kicking her feet.
ME: Julia, you wanted to go to the playground today, but the answer is absolutely no, because you are not on nice behavior.
JULIA: Yes, we ARE going.
ME: No, I'm sorry, you're not on nice behavior.
JULIA: I don't WANT to be nice. I want to be MEAN.
ME: Okay, that's fine, but I don't want to talk to you if you're being mean, so as soon as you've decided you're ready to be nice, I'm ready to listen.
JULIA: Putting a little doggie toy of Madeleine's on top of the Leapfrog table, then ripping it out of Madeleine's hand as soon as she grabs it. Twice.
ME: Julia, please stop grabbing that away from Madeleine. That's her toy, and it's really not nice of you to grab it from her as soon as she gets her hands on it. That's teasing her, and it's not nice.
JULIA: No, it's not nice to HER!
ME: That's right. It's NOT nice to Madeleine when you tease her.
JULIA: No, it's not nice to YOU!
ME: You're right, it's not nice to me. It makes my heart really sad when I see you teasing your sister.
JULIA: No, it's not nice to ME!
ME: Well, I'm glad you're recognizing that it doesn't feel nice to you when you tease your sister. That means you're showing compassion.
JULIA: (angrily) Mommy, I want you to tease me.
ME: Ignoring her.
JULIA: Mommy, I want you to tease ME.
ME: Ignoring her.
JULIA: Mommy, I WANT YOU TO TEASE ME.
ME: Ignoring her.
JULIA: Putting her play phone on the Leapfrog table.
MADELEINE: Grabbing at it.
JULIA: Mommy, that is NOT my phone. That's a baby toy.
ME: Oh, how nice of you to share it with Madeleine. Here, Madeleine, you can use this.
JULIA: Mommy, I'm not sharing. It is NOT mine. It's a BABY toy.
ME: picking up Madeleine and letting her play with the phone on my lap.
JULIA: Mommy, I do NOT want Madeleine using that. That's MY phone and she can't use it.
ME: Oh, well, you just told me it's a baby toy and it's not yours, so I'm letting Madeleine play with it.
JULIA: No, she can't play with it. That's MY toy.
ME: Well, maybe you should have thought about that before you said it's a baby toy.
JULIA: bringing one of Madeleine's toys over to exchange with the phone.
ME: You need to say, Madeleine, may I have my phone, please?
JULIA: Madeleine, may I have my phone please?
ME: Yes, of course you may Julia, thank you for sharing.

Fifteen minutes later...
JULIA: Mommy, can we please do something fun today?
ME: No, Julia. You blew it.
JULIA: No, I did NOT blew it. Mommy, I did NOT blew it. MOMMY! I did NOT BLEW IT!
Here we go again.......