“What was I... Ah yes, YES, YES, YES!”
“Get out of my room!”
“I have a party to go to...”
Your sister is this really nice girl I met in a kitchen at some sweaty, hungry student party once. We're talking a skirt shorter than her belt, a tube top less modest than Hasslehoff discussing the fall of the Berlin Wall, and a crotchless thong that screamed: wrong, wrong wrong. She wasn't even wearing a bra, she said she'd lost it in the woods! She was most certainly drunk too, I attributed that to her consumption of alcohol. It wasn't hard to get her to come out with me, I just told her I had my own pulse. She said she'd come back with me and she did. We did it right there on the park bench. Haven't seen her since.
References to your Sister in Popular Culture
Your sister is every single look and nothing. Your sister is a dude with a VERY BIG secret!
Encyclopedic comparisons to YOUR sister
Your sister's dirtier than Christina Aguilera at an orgy on a pig farm. Hornier than a sexually deviant Rhino. Hotter than Kylie Minougue lying on a sun-bed in the middle of the Sahara Desert. She's easier than going first in a game of 'Connect One'. Looser than a pair of jeans bought in 2004 by this year's Weight Watcher of the Year, which even at time of purchase were a little on the large side. She's put it about so much, she's only managed to narrow down the father of her child to a gender.
And she's good at Scrabble.
Beating Your sister
Also the ultimate come back for people tired of using 'your mom'. Nothing beats 'your sister', unless of course the other person responds with 'your sister and your mother in the same night.*' This is pretty advanced word-play however, and you would be unlucky to face such complex and intellectual banter from someone without a PhD in Disrespect.