The girl I am sleeping with right now pulled that move off ON HER OWN a few weeks ago. She was blowing me and took it out of her mouth, held it with her hand and slapped it on her toungue and cheek. It was quite impressive.
i do that just about everyday. my girlfriend sticks her tongue out and i smack it a few times. its also fun to smack her forehead, it makes a loud WHACK.