As the boss, I call you up on your day off to get you to do some extra work. You're a loser with no life so you should have a lot of free time. Your coworkers and I have other things we want to do so I am going to assign you some extra work. You will be doing THEIR work and yours as well and I expect you to do it quickly.

Why should we have to waste our time working when we can go out and have fun and leave the work to the loser? You're going to say yes because I am the boss and I get to tell you what to do!