“I don’t blame you, dear,” she assured Harry, tipping eight or nine sausages onto his plate.
“Arthur and I have been worried about you, too.
Just last night we were saying we’d come and get you ourselves if you hadn’t written back to Ron by Friday.
But really”, “flying an illegal car halfway across the country — anyone could have seen you —”
She flicked her wand casually at the dishes in the sink, which began to clean themselves, clinking gently in the background.
“It was cloudy, Mum!” said Fred.
“You keep your mouth closed while you’re eating!” Mrs. Weasley snapped.
“They were starving him, Mum!” said George.
“And you!” said Mrs. Weasley, but it was with a slightly softened expression that she started cutting Harry bread and buttering it for him.
As I understand, Fred said "It was cloudy", he means the weather is cloudy so no one could see them from the ground. But I don't quite get "They were starving him" by George. What does "they" refer to? It sounds like a joke, which I fail to understand.
-- From Harry Potter.