a slanderizing of female genetillia referring to the curtian like appearance of the labia (majora). the "beef" comes from the flesyness of the vagina, meat is also used as a casual refrence to male genetillia "beat your meat".
"the beef curtians opened, she was ready to start the show."
Flaps not of the freshest kind. Also Too much cheese on the tacco
you better step if you think im chubachaing those beef curtains