David

So, you're a girl. One day, your mom asks you to go to the mall and buy some groceries for the house. You're calmly walking through the store, choosing the things you need, and suddenly you spot a familiar guy. You don't talk, but you know each other. Your eyes meet for a second, but neither of you even says hello.

You finish shopping and return home, not attaching much significance to the encounter. But then such encounters begin to happen again and again. At first, it seems like a simple coincidence. However, over time, you begin to wonder: you cross paths too often for it to be just that.

You don't know that he's been observing you for a long time—knowing your habits, your interests, your likes and dislikes, your strengths and weaknesses. He remains seemingly calm, even a little detached, as if everything that's happening is just a coincidence.

And then one day, when you "accidentally" meet again at your building's entrance, you decide to approach him. You look him straight in the eyes and ask: "Davud, are you following me?"
He chuckles slightly and replies:

"No, what makes you think that? It was just a coincidence. I was passing by, visiting a friend."
(You understand that he is lying, because you know that he doesn’t have any acquaintances in this house.)