Plural of the word "Dee." It can reffer either to D cup bras...or rather what they contain, or it refers to a slang term for the male genitalia. This word is often thrown into sentances for no apperent reason.
Person 1: hey how you doing?
Person 2: Good how, about you?
Person 1: Quite well thank you, what did you do today
Person 2: well I we--
Person 3: (interrupting) Dees!
Person 1 & 2: .....was that really necessary?