monkey business

I’m going to take off the cuffs, Slim, and off you, Jerry. But don’t try any monkey business. When Peters answers the door, you tell him everything’s O. K., and that you’re the committee, see? Once the door’s open, we’ll do the rest.

1918 December 10, J[oseph] Allan Dunn, “The Man With the Mole”, in Detective Story Magazine, volume XIX, number 5, New York, N.Y.: Street & Smith Corporation, →OCLC, chapter VIII (The End of Baldy), page 39, column 1

I'm looking for monkey business / Just playing around / I'm here on monkey business / And look what I found

2020 January 24, Neil Tennant, Chris Lowe, “Monkey Business”, in Hotspot, performed by the Pet Shop Boys

If you ever hear a man talking about his duty as a citizen, by the Living Jingo dont trust him. … He's up to some kind of monkey business nine times out of ten. You dont know what a relief it is to me that you and Joe are comfortably settled in life.

1925, John Dos Passos, “Revolving Doors”, in Manhattan Transfer, New York, N.Y.; London: Harper & Brothers, →OCLC, 3rd section, page 328