From 'Dirty Dancing', 'I carried a watermelon' is when an innocent looking cute girl has slept with so many guys at the hotel, the only thing that is going to satisfy her at the party is a giant watermelon.
'I carried a watermelon' is a polite way for upper class girls to say they have fucked everyone in the hotel, school and university, and now only
a watermelon can satisfy them sexually. See
Annabel Chong or
Scarlett O'Hara.
Example:
Baby walks into the busy party, meets a cute guy.
BABY: (looking down and shy) I carried a watermelon.
JOHNY: I know baby your a slut!
PENNY: Don't do it Johny! Don't fuck that rich bitch! She's not only carrying a watermelon, but she's probably carrying AIDS!
JOHNY: Don't be a jealous skank Penny, and
you know that's not polite to speak to the hotel patrons like that. Instead of saying she has AIDS, next time use
the rich bitch term and say she has a
House in Virginia!
Penny shits on the ground in front of the packed party and walks out in disgust!