be up to your (old) tricks
US /bi ʌp tu jʊər (oʊld) trɪks/
UK /bi ʌp tu jʊər (oʊld) trɪks/
1.
to be doing something bad or dishonest, especially something that you have done before
:
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I saw him sneaking out with a bag of cookies; he must be up to his old tricks again.
•
The cat has been unusually quiet; I bet she's up to her old tricks, probably trying to get into the pantry.