You are hard Gee

I wouldn't actually call it spoon feeding - just being considerate and noticing when the mood has changed - even if just for my own sake. As a PA working closely with someone, you can't help notice changes when perhaps someone else wouldn't. I am certain he doesn't expect to be treated differently when he is like this and I don't go over the top but it does no harm to be kind and make a simple gesture, in my case, tea and biccys - this may go towards him calming down and therefore making my day easier.
I wouldn't actually ask what is wrong - if work related he would say if he wanted me to do anything and I wouldn't really want to know if personal but he usually come out of it and the mood lifts.
He is human after all and we all have our off days.