monkey business

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!
Categories: business informal noun slang