I do it once in a while, the one and last time I did it at work this girl flew out of her shoes and screamed the living day lights, thank god she had a sense of humour. the other day my wife comes home and I pretended not to be there but when she put her coat in the closet I was in there and grab her, she went flying back screaming, it was a moment of pure hell for her but she relaxed and started to laugh about it. Does anyone else do this.