up to one's old tricks

up to (one's) old tricks

Doing things that one was known for doing in the past, especially deceitful or mischievous behavior. Food went missing from the school cafeteria? It sounds like Billy Evans is up to his old tricks again. I reunited with my two best friends after nearly 5 years apart, and we were up to our old tricks again in no time.
See also: old, trick, up

up to one's old tricks

Behaving in one's usual deceitful or mischievous fashion, as in She's up to her old tricks, telling her parents one thing and her teachers another, or He's up to his old tricks, teasing his sisters until they're in tears. Put as at his old tricks, this idiom was first recorded in 1823.
See also: old, trick, up