"Ouch!" Percy yelped even though her pinch hadn't hurt all that much. It was more of a knee-jerk reaction and shock that the woman had actually pinched him. It proved she was tangible, yes indeed, but not that she was who she claimed to be however much the looks resembled the description he had heard.
"We could both very well be dead, if you're truly Mrs. Potter.." he trailed off with no small amount of skepticism in his voice. How could he have possibly died when he was in perfect health? No one wanted to assassinate him (or, no one that he knew of).
Struggling to suspend disbelief, he finally answered her question. "I'm Percival Weasley, but I prefer to be called Percy. I went to Hogwarts with your son, Harry."