What's the cruelest trick anybody has ever done to you?

When I was about 13, my parents went out for the night and left my two brothers and I at home. I was in bed reading and fell asleep with the light on. I woke up to heavy, raspy breathing in my face. I opened my eyes and my dad was about two inches from my face with a solid white Mardi Gras mask on. You know, the kind with only eye holes but covers the whole face? I started screaming and ran out of my room before I even realized it was him. In doing this, I woke my little brother up who immediatly started screaming as well. When he ran down the hall, my dad started chasing him back to his room. After a minute, we realized what had happened. We were livid, to say the least.