Oh my! I have the same kid....only mine is 3! His mom severely micromanages him and I think that messes with his emotional stability.
Yesterday they were 2 hours late getting here. She said it was because he wanted to wear his puddle boots instead of the shoes she had out for him.... so she had a power struggle with him until she won and they managed to get here but 2 hours late!
Then when the boy is here, he is so full of anxiety that he will literally stand around and just cry. (I used to think for no reason) but I am starting to think it is just his way of letting out steam from all the pent up anxiety his mom is putting on him.
I hope your crier starts smiling more!!