I'm compassionate, but I'm not a doormat.
This occurred on Saturday. He had Sunday off. There were two days that he could have made arrangements with the other two members of management to get his shifts covered not assumed that I would just cover it.
Instead of taking ten minutes on Sunday to find people to get some coverage (the other supervisor offered to help him out a little by coming in earlier) he just said, "No, she's just going to have to cover it."
In theory, he could just quit. If he had, then I would have been in a pinch, but I would have found some way to make it work. I'm sure he could find some other job somewhere else that pays less than what he's making now and actually expects him to put forth some effort in his job because there are ten more people waiting to take his place.
I may seem like a mean person for this, but lack of planning on his part doesn't constitute an emergency on mine.