He thought you were some random bulgur that he had to stop, he's Spider-man it's his job anyway. Athough when he took off your mask and saw your face; you looked too much like him and someone he closely knows.

He can't comment on your face without blowing up his secret identity, so Peter asks the safe question, "Who are you?"

He has some suspicious, considering your looks and how young you seem to be. Oh boy he's nervous.