a sex move for a gay orgy. the first man, or foundation, lays with his back slanted, and puts his penis in the anus of the second man, floor 1. floor 1 then puts his penis in the anus of the third man, or floor 2. you keep adding floors until you eventually have the last man, or the roof. the roof is masturbating while being penetrated.
man one: hey boys, wanna do the empire state building tonight?
man two: sure, just let me be the roof
man one: ok