The story behind this photo is that every time I give Little Man a bone, I play a game with him like I’m going to take it. He loves the game, where I chase him all over the house yelling “I’m gonna get dat bone! I’m gonna get it! I’m gonna get dat bone!” If I stop he will come and sit down right next to me, chewing and staring at me from the corner of his eye, daring me to try to take it.  Then the chase is on again.

But, eventually, he tires of the game (I never do) and wants to get to work on the bone. This is right at the point, about half an hour into it, where he is getting fed up playing and just wants to chow on it.

Found on the following Wikipedia articles:
Dog communication
Animal communication

Okay, he’s had enough.
Found on Chihuahua