An ikea flat packbox is a term given to a disabled person whos joints like knees, shoulders, hips and jaws can pop out of there sockets with ease. This can be used as an insult or description however this does depend on said situation.
"oh hey do you know jack" - Person 1
"no which one is he?" - Person 2
"Ikea flat pack box" - Person 1
"ahh right" - Person 2
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi