Pull someone's leg

Pull someone's leg

Meaning:

Tease someone by saying something shocking as a joke.

If you pull someone's leg, you tell him/her something that is not true as a joke.

Example:

She said she found $1 million in the park, but I think she was just pulling my leg.

Don't worry. I won't tell it to anyone. I was just pulling your leg. (It was a joke.)