Harry had been surprised, then pleased when his own reflexive maneuver had been repeated by this other wizard. Given, he had no idea what that was coming out from behind the cover, but he was an Auror, and strange things jumping out at you was par for the course. Although he'd drawn his own wand a split second after the younger wizard, he obviously didn't need to use it. Someone had trained the other man well.
Sliding it away, and readjusting his dusty clothes, he at first didn't see the look the young man gave him. However, he was completely perplexed at the address. "I'm sorry," Harry managed, with a sheepish smile. "I don't usually get mistaken for someone else's father. My own brood is quite....distinctive."