Well, not really a sex story but...
My ex bf and I were in "the rack" of his fraternity house just making out when the door opens and in staggers one of his brothers, completely wasted. The guy figures out what's going on since, well....my ex is on top of me at this point....and proceeds to apologize a lot and leaves with the door closing behind him
....then we heard this godawful clatter and some stiffled moans....
the drunk brother had fallen down the very narrow stairs leading to the rack
no worries, he lived.