This is based on an expierence with my own cousin. If you don't know the song that goes 'This old man, he played one. He played knick-knack on my thumb. With a knick-knack, patty-whack, give a dog a bone! This old man came rolling home!', then you won't understand most of this fanfic. If you do, however, sing it to yourself and keep in mind what it sounds like when you sing 'this old man'.
Christmas was coming soon. Two four year-olds sat cross-legged next to the fire happily cutting away at paper snowflakes. Even if they became torn or ripped or came out completely messed up, their mum still taped them on the wall. The shorter of the two, a girl with black hair and cinnamon eyes, began to hum a Muggle song that Granddad Weasley had taught to her to herself. Her brother caught on quickly as to what she was humming, and began to hum the tune as well. Soon, they were singing loudly as they happily snipped paper snowflakes.
"This old man, he played four. He played knick-knack on my door! With a knick-knack patty-whack, give the dog a bone! This old man came rolling home!" Fred prepared to go onto the next verse, but Roxanne stopped.
"You're saying it wrong!" she cried indigently.
"What d'you mean?" Fred inquired.
"You're saying 'this old man'!" she exclaimed. "It's 'whistle man'!"
"No it's not!" Fred argued. "It's this old man. You can ask Granddad Weasley yourself."
"Nuh-huh!" Roxanne persisted stubbornly
"Uh-huh!" Fred shouted back.
"MUM!" The two chorused angrily. Roxanne shot him a sharp glare. "Who's right?"
"What do you mean?" she asked.
"Who's right?" Fred repeated. "Is it 'whistle man' or 'this old man'?"
"Whistle man!" Roxanne exclaimed.
"This old man!" Fred argued.
"Calm down!" Angelina separated them quickly. "What's the problem?"
"You know that song Granddad Weasley taught us?" Roxanne explained. "The one that goes 'Whistle man, he played one. He played knick-knack on my thumb. With a knick-knack, patty-whack, give a dog a bone. WHISTLE MAN came rolling home'? Well, Fred thinks it's this old-"
"I don't think! I know!" Fred interjected.
"You don't know anything!" Roxanne exclaimed.
Angelina sighed. She knew her pride and stubbornness would not let her children stop arguing. She had to reach a compromise.
"How about on even number, we say 'this old man', and on odd ones, we say 'whistle man'?" she suggested. The twins didn't seem to know the difference between odd and even. "How about you two ask Granddad Weasley when we go to the Burrow for Christmas?"
"Then you'll see!" Roxanne agreed.
The two went back to cutting up paper snowflakes and were talking about something that was probably as equally absurd as the right lyrics to the song. Angelina sighed again, the time in relief. She walked back over to where George was sitting and collapsed down in the chair.
"Don't think this is over," George warned her. "Even when she finds out that it's 'this old man', Roxie's still going to say 'whistle man'. They'll quarrel about this again at some point."
"How do you know?" Angelina asked nervously.
"Have you ever met a four year-old before?" George asked. "Talk about a case of stubbornness!"
Sing the 'this old man' part again. Doesn't it sound like 'whistle man'? The first time I heard my cousin sing this song, I couldn't tell if she was saying this old man, whistle man or thistle man.