My sisters are 14 and 10, and my brother is 7. The ten-year-old is easiest to screw with.

We have some lamps on timers at our house, and last time she was here she saw one switch on. She asked wtf so I told her with a straight face "Oh, that was just the ghost. He does that sometimes."

She wigged. It was awesome.

A couple of years ago for Christmas I gave her Sea Monkeys and told her that when they get big enough she has to start feeding them chicken, and then they'll get bigger and she can move them to the bathtub and they'll eventually grow into mermaids.

And I don't remember why, but recently I was mocking her for being a baby murderer, which she found amusing.

Last year for Christmas I bought her a Littlest Pet Shop set that had a small lady bug with a big flower hat and sunglasses, so I told her the lady bug was a pimp and taught her to say "Pimpin' ain't easy but it's necessary." Which she promptly told to her teacher. Ha!

And my little brother has been Rick Rolling me on Y!M and Facebook at every opportunity for a week. I told him to knock it off so he said "ok"... and then promply Rick Rolled me in Japanese.