Casen's Sign Language

We've done a little sign language with Case - just a few signs for main words that he needs to use. He has morphed the signs into his own little sign language.
His favorite sign and word is "more". More food. More drink. More play. More open the door for me. More playtime in the sunroom. More playtime with the dogs. As you can probably guess, we usually have to figure out what he is asking more specifically. Usually it's food though. So that's our first guess.
He knows the sign for dog so he does it from time to time (it's panting like a dog). He now usually likes to just say, "Dog." Over and over again.
I decided a couple weeks ago that he needs to start learning to say please and thank you. We taught him please (it's rubbing your chest right below your neck). He did not really want to have to say or sign that word. Why does he need to do that when he already said, "More?" At first he would either walk away and try again later if we insisted he say please OR he would do the sign on our stomachs. We let it count. Then it changed into him doing the sign on himself but usually it's on his stomach or chest - all over rubbing and haphazardly done, as if he is saying, "Okay, okay, please." A few days ago, I told him he had to ask please before he could have whatever I was eating. He did the sign for please and shouted, "No!" I told him it didn't count so he finally just made the sign. Stubborn boy. But very entertaining boy.
Today he came over and asked for more (made the sign) drink and made the please sign! Without prodding! Woohoo!
I guess we are going to introduce Thank You later this week. He's going to love that-he already will have gotten what he asked for. We'll see how it goes....