A friend of mine was telling me the story of how she was taking her dog for a walk and saw someone she thought she recognized approaching her. She called out "Hi Sexy!" But the person wasn't who she thought it was and she was immediately embarrassed.
I think this has happened to all of us at one point or another. I'm reminded of the scene in "The Cowboy Way," where Woody Harrelson's character grabs a lady's butt and it turns out to be someone else. Of course the movie is scripted and he delivers a punchline.