Blue door 

Blue doors indicate a place where evil lurks. It is most often a secret communication to other evil-doers, informing them it is one of their establishments. Any number of evil rituals happen in these establishments in secret (ie: after hours, hidden rooms, etc)

“Oh look Hillary, that bar has blue doors.”

“Duh, Bill, we’re having pizza with walnut sauce there tonight with Marina and John!”

“Yum! Hopefully hotdogs with maps too!”

Blue door by bbnico June 15, 2019

Blue Door 

Often inhabited by Criminals and Scumbags

Dude 1: "I saw a guy getting arrested in his blue doored house the other day"
Dude 2: "What a scumbag"

Blue Door by Herrothere123 July 6, 2010

Blue Door Kid 

A scummy child, teenager or young adult that lives in a council house. This name is apparent as most council houses have blue doors.

Blue Door Kids are often a nuisance and just make the place look untidy in their tracksuits.

Person 1: Wow! What a fucking chav!

Person 2: Yeah; complete Blue Door Kid.

Blue Door Kid by that.kid.over.there March 14, 2011

Door Knob Blue Balls

When you're on your way to getting laid but then the girl hears the sound of a door knob and she is suddenly freaked out and you know there is no way you're getting her back into the mood.

"She was just sliding off her panties when her parents got home and she heard the front door knob. There was no way she was putting out after that. Nothing sucks worse than door knob blue balls."

Door Knob Blue Balls by Floppage January 11, 2012