I think it may just be street slang. There was a tale in Reader's Digest's Life in These United States of a young couple who had met in Viet Nam while he was over there in the not so recent unpleasantries. Everyone in the suburban neighborhood thought it was so cute when she said how nice it was to live in a 'cuddle sack'. My suspicion was that the French that was used in Viet Nam included the not so nice version of cul-de-sac and she couldn't imagine all these innocent Americans saying they lived in an asshole, so she must be mishearing it.