Tact Much?
Lisa, you still missed about 90% of the point here. He grinned because he was subtly letting you know he was single. That said, there is scientific evidence to support your “issue.” Women use both sides of their brains to process language, not just interpreting words but also emotions through facial expressions and tones.
Conversely, men tend to process language primarily with the left side of their brains, focusing more on the words themselves to gather information. It’s no wonder men and women often have difficulty communicating; we literally listen differently. At least science has offered some insights into this age-old mystery.