I'm still mad at you...

Let me preface this story with saying that I'm very open with my children about emotions. If Moose is making me angry, I will tell him in those words. He knows the words angry, mad and frustrated. He uses them too. We're also very open with positive and happy emotions as well. We've also been having a problem with Moose and going potty. I always have Moose go before his nap and before bed. He has the habit of saying "But I don't have anything." However, I am always right. He always has something. This has been a bit of a problem lately, because I'm tired of his retort. So this is what happened today:

Me: Please go potty, it's naptime.
Moose: But I don't have anything.
Me: Do I like when you say that?
Moose: No.
Me: So go potty please.

He then went to the bathroom and came back after about 10 seconds saying he "didn't have anything". I told him to go back and sit longer and that's when he starting fighting back. Ultimately he was told to get on the potty or he would lose his book and song for naptime and have no fun privileges afterwards. (movie.) With that ultimatum, he went to the bathroom. He comes out a few minutes later and stands next to me silently.

Me: So?
Moose: I had pee.
Me: Good. Go flush the toilet and wash your hands.
Moose: But I'm still mad at you.
Me: That's fine. Go flush the toilet and wash your hands.

We encourage identifying our emotions and expressing them. As long as you still flush the toilet and wash your hands.