Mrs Weasley was giggling to herself one evening, and Arthur Weasley, intrigued, asked her: “what’s so funny, darling?”
Looking up at her husband, she cleared her throat, stifled her laughter, and said, “I was walking by the living room when I heard Bill and Charlie talking.”
“Oh?” Arthur didn’t understand what was so funny about this.
“They were angry at each other,” Mrs Weasley continued. “Bill said to Charlie, ‘anything that comes out of your mouth is stupid!’ And Charlie looked him right in the eye and said, ‘Bill.’”
A few moments later, an annoyed Bill Weasley walked in on the bewildering sight of both his parents laughing themselves silly.