The Collaborative International Dictionary
To monkey with
Monkey \Mon"key\, v. t. & i. To act or treat as a monkey does; to ape; to act in a grotesque or meddlesome manner.
To monkey with, To monkey around with, to handle in a meddlesome manner. [Colloq.]
Usage examples of "to monkey with".
But I didn't know why, and it never would have occurred to me to relate the bull's showy apparatus with those things I possessed, in so slight a degree, and which I wasn't to monkey with.
These Voth brothers are from far off in that other land, and they've got things I don't know how to monkey with.
I did it because she was all guts and gallantry but too ignorant to be allowed to monkey with such a buzz saw.