Well, respectfully, I've actually had that happen, and in a business setting! I was sitting at my desk, but had swiveled my chair sideways to talk with her, and she had pulled up a side chair. I was amused and begin smiling even while I was talking. When she looked up, I kept smiling and winked at her. She blushed, but we continued the conversation and then she left. Neither one of us ever said anything about it - though if I hadn't already been committed to someone else, I probably would have followed up. She was a cutie!