Couple of years ago I was @ a friend's family get-together... huge party.

I'm talking with this girl, everything is going fine. I ask her what school does she go to, and she says ABC - which was, the same school as my sister.

So, immediately I ask her (kind of excited) if she knows "Mary Turtle" (my sister, although I didn't say "she's my sister").

As soon as she hears "Mary Turtle", she tells me "AH! I hate that girl! She's a bitch... blah... blah..."

And I just started laughing my ass off... then my friend comes along, he asks what the hell happens - I was still laughing - and the girl rewinds for him the conversation...

Then my friend laughs out loud, and tells her: "You dumbass, Mary Turtle is his sister!"