Como dizer "Vá pentear macacos" em inglês

Go fly a kite.

You say "go fly a kite" to tell someone to go to another place and do something different; leave here (agressive). Example: "Oh- not you again!" Reply: "Hey, why don't you go fly a kite?"

Go fly a kite can be considered rude or aggresive because you are abruptly telling the other person to go away.
http://www.goenglish.com/Idioms/GoFlyAKite.asp