After Harry and Dudley get attacked by Dementors in the alley, they come home, and Dudley is still dazed by the attack Petunia:"Dudley, is that you?"

Petunia sees Harry holding up Dudley as a crutch

Petunia:"Vernon! Come quick!"

Vernon: "Who did this to you, boy?!"

Dudley points at Harry

Vernon: "Happy, are we... now? You finally done it. You finally driven him loopy."

Petunia: "Vernon, don't say it like that."

Vernon:"Look at him Petunia he's gone nutters. I reach my limit,do you hear? This is the last time I'm take of you and your nonsense"