MONKEY BUSINESS

{n.}, {slang}, {informal} 1. Any unethical, illegitimate, or objectionable activity that is furtive or deceitful, e.g., undercover sexual advances, cheating, misuse of public funds, etc. * /There is a lot of monkey business going on in that firm; you'd better watch out who you deal with!/ 2. Comical or silly actions; goofing off. * /Come on boys, let's cut out the monkey business and get down to work!/