When there is a very large discrepancy among siblings in hotness. Usually used when one sibling is very attractive, and the other one has been beaten severely with the ugly stick.
Minnix: God damn Alisha is so hot- I think she is the hottest bartender in the whole city.

Matt: Have you met her sister Jen?

Minnix: No- but I hope I do soon, thank god there are two of them...

Matt: Not so fast- there is some serious sibcrepancy there- Jen looks like someone punched her in the mouth with a fistfull of shit.

Minnix: Oh man, that's terrible-that means you aren't guaranteed to have a good looking kid with Alisha. Her stock just plummeted. How depressing.
by schmuckaneers May 13, 2009
Get the sibcrepancy mug.