Everything about him would have been perfectly normal.
If only he didn't try to start a conversation with
"You have a mustache"

to a girl

He looked puzzled and a bit lost.
Not the child kind of puzzled.
He was the grown up puzzled, the I can't find my to so and so kind of puzzled.

He stopped and stared and hesitated.

Then he threw out the sentence. He wasn't questioning, it was a fact.
He seemed to want to start a conversation or ask something else.

She stopped talking the moment he stopped and stared.
He made her feel uncomfortable.
She giggled nervously.
The "you have a mustache" line froze her.
She didn't know what to do.