Who's in charge?

It's pretty clear to us that Zorro knows what "come" means. Trouble is, he views it as a suggestion, not a command. Case in point: he has recently picked up the habit of crawling into our bed when we're not in it. When we order him to get off, he just looks bored. He will vacate if pushed, but not without an annoyed grunt. Something else to work on in obedience school, I suppose.