It's impossible to definitively know what a guy is thinking just by observing his facial expression. He might be:
- Thinking about something else entirely. Perhaps he's lost in thought, distracted by something in the background, or simply daydreaming.
- Feeling shy or nervous. Some people find it difficult to smile, especially when they're around someone they find attractive.
- Trying to gauge your reaction. He might be observing your behavior and trying to understand your feelings towards him.
- Not interested in you romantically. This is a possibility, but it's important not to jump to conclusions.
It's best to avoid overanalyzing a single action and instead focus on communicating with the person directly if you're curious about their feelings.
