Your friend wants you to do something for them — lie to a teacher about where they were, maybe, or give them the answers to something. You're not comfortable with it. And the moment you hesitate, out comes the line: "If you were really my friend, you'd do it. I'd do it for you." It works on you instantly. You don't want to be a bad friend. You want to prove you care. And suddenly the thing you didn't want to do feels like the only way to show you're loyal — as if saying no would mean the friendship was fake all along.