"Odd Squirrel"

Marty's buddy in that car refers to having an "odd squirrel" referencing the nurses in the back seat.

I wonder if "squirrel" was used at the time as guys today would say "pussy" or "beaver." Although I would think that the nurses would have heard the remark (even though the driver was whispering.) Or maybe these nurses couldn't care less, they were DTF.

I think there were supposed to be two nurses and two dudes already in the car, so there should not have been an "odd number." Maybe I got the numbers wrong...