Vocabulay

Hello everyone,

Is there any word in English to describe the following?

"When you attach your forfinger mostly middle finger to the thumb with force, and then you release your middle finger to hit something small, e.g. "a fly or a small insect" or someone's cheek or any part. It is somehow painful when we do it to someone as a friendly way. But if you do it with force it is so painful."

My explanation is somewhat long. I'm sorry about that. I hope you give me a word or some words to describle that.

Kind regards,

JA