Revenge Gone Wrong

When the coast was clear, I tiptoed down the hallway toward Mark’s bedroom. I then positioned a thumbtack, pointy-side-up, in his doorway. My plan:
1. Mark would step on the tack, and feel pain.
2. I would not get caught.
Hours later, I heard a booming “OWWW!!!”
When I arrived on the scene, a barefoot Mom was on the floor. A blood drop replaced the thumbtack she’d just extracted from her heel. Hurt, she wondered who could be so careless. That her youngest daughter was a conniving revenge artist never entered her mind.
I saw no benefit to clouding her view, so I buried my guilt and tsk-tsked alongside her.