You (holding watermelon): I carried a 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.
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!