What does it mean when a guy tilts his head to the side and smiles?

[Crystal]

I'm good friends with this guy and we had made plans to go out together and eat somewhere to catch up on life. We were both sitting at a booth and he was talking to me. After he was done talking, we both went silent for a moment. I had looked down for a second, but then when I looked back up at him, I found him staring and smiling at me with his head tilted to the side. His eyes were also slightly crinkled while he was staring at me. Then, he started talking about something else. What does it mean when a guy looks at a woman like this?

[Jackdean]

he might have a crush on you, it's a decent chance. he also might just be happy to see you again

[Jerome]

I think he acted that way because he felt you were shy and decided to look down. Hence, he was probably smiling.

[Dennis]

Nobody can tell why he acted that way, only him knows what he was thinking at that time.