Means 'dick in a box'
Comes from the awesome music video featuring Justin Timberlake and Andy Samberg which was shown on Saturday Night live.
The video rips the shit out of
sex music of the early 90's. Its about two Cassanova men who attach boxes to their waists and have their dicks in the boxes. They then present the box to their lovers as a Christmas gift or any occasion for that matter:
'Christmas...
dick in a box, Hanukkah... dick in a box, Kwanzaa... a dick in a box, Every single holiday a dick in a box, Over at your parent's house a dick in a box
Mid day at the grocery store a dick in a box...'
Some complete legends who live in
southsea discovered this video and after watching it over and over it, the phrase dick in a box became abbreviated to
DIAB and used as an insult.