catch sb with one's hand in the cookie jar

/kˈatʃ ˌɛsbˈiː wɪð wˈɒnz hˈand ɪnðə kˈʊki dʒˈɑː/

/kˈætʃ ˌɛsbˈiː wɪð wˈʌnz hˈænd ɪnðə kˈʊki dʒˈɑːɹ/

[phrase]

catch sb with one's hand in the cookie jar

[PHRASE]

to catch someone in the act of doing something wrong or inappropriate

Examples

1. The Bulldogs star knew she had to be careful playing with four fouls, but after a Williams rebound, Vivians got caught with her hand in the cookie jar and fouled out just a minute into OT.

2. Mr. Osbourne, you sound like a boy who's been caught with his hand in the cookie jar.