Adjective used to refer to a person usually male who will have sex with any woman. Someone who is so indiscriminate that they would fuck a female monkey. Eventually its use was broadened so that it became used to describe anyone whose habits are unpleasant, unsavoury or just plain weird.
"Malcolm, you are, without doubt, the most useless cunt eyed, shit-licking, monkey fucking, piss-brained, ass kissing, fuck witted WOSP in the world!"
The first time I ever heard this saying was on a construction site where I continued to hear it quite regularly. Basically it means fucking something up. Trying to do something that may require a little bit of skill,experience or coordination and fumbling around with it and not getting it right. Picture a monkey all excited trying to get a hold of a football so he could hump it.
Applying for fall classes, I had to register with the burser, the advisor, check my prereq.s, and then stand in line, and then I found the class I wanted was closed out. "Man scheduling for classes this morning was like a monkey fucking a football"
Bill - Did you go to the concert last night?
John - Yeah, dude it was like a monkey fucking a football, the organizers better get their shit together next time.