Teddy Lupin's real name is Edward but sometimes Victoire Weasley called him Theodore and he hates it when she does that. Although in payback he calls her Vicky and she hates that. One day he asked her why.
"It makes me seem like a bloody child! I'm fourteen for heaven's sake" Victoire had exclaimed.
"Oh yes, at fourteen you're obviously a full-fledged adult. My mistake. Also don't say 'bloody'" he said.
"You're not my dad Teddy, don't tell me what to do. Besides, why would you insist on being called Teddy? Theodore is much more mature."
"Well Vicky for starters, Theodore isn't even my name. And besides, a name is hardly a measure of maturity."
"Vicky is not my name either!"
"It's closer than Theodore, Vicky."
"I swear to God, Edward Remus Lupin, if you call me Vicky one more time, I will hex you all the way to Egypt!"
"Aww little icky-vicky's got her panties in a twist. You can't hex me to anywhere Vicky. One, you're rubbish at charms and two, I'm Hogwart's golden boy." He said smirking victoriously at her threat.

At that moment Edward Remus Lupin had made a very big mistake. By bringing up an even more hated nickname than Vicky (Icky-Vicky was just truly more atrocious), Teddy had ignited Victoire Weasley's Veela anger. Well, her one-eighth-Veela anger. She schooled her expression in to a stony glare, muttered something along the lines of "you'll be sorry Lupin," and marched to her bedroom.

She proceeded to plot instead of doing her charms homework and finally came up with the ultimate comeback. Howlers, apparently, were remarkably easy to obtain. Especially when your last name was Weasley. She sent the blank Howler to Lily Potter with minimal instructions and just emphasizing that she had to use a certain nickname when addressing Teddy. Two things about Lily Potter: one, she was the sweetest child ever, two, she was the loudest child ever. Sweet Lily would never utilize the howler for its intended purpose, but she could still wreck certain damage.

So Victoire Weasley went to breakfast every day and bided her time. She only had to wait a week before she saw the Potter's family owl swooping into the Great Hall with a tell-tale red letter.
"Bloody hell, Teddy you have a howler." Jonah McEllwan muttered eyeing the letter cautiously.
"Why would I get a howler?" Teddy puzzled, poking at the letter.
"You better open it mate, it only—" McEllwan began before the letter suddenly burst into life.
"TEDDY-BEAR! ISN'T THIS LETTER SO COOL? VICTORIE TOLD ME HOW TO USE IT! I CAN'T WAIT TO SEE YOU! ALBUS AND I WANT TO HEAR ALL ABOUT HOGWARTS. PLEASE WRITE TO ME TEDDY-BEAR!"
There was dead silence for a moment. Teddy's hair turned a violent shade of pink and the Great Hall erupted into laughter. James Potter had to be patted in the back repeatedly as he all but choked on his Pumpkin Juice. Domnique Weasley was almost as red as hair from laughing so hard over at the Ravenclaw table and even Scorpius Malfoy cackled from the Slytherin table. Victoire hid behind her copy of the Daily Prophet but peeked out to just in time to lock eyes with Teddy. He was furious to say the least and for a moment Victoire was a little scared. She hadn't expected Lily to throw her under the bus like that. But the moment passed when she couldn't help but snicker at Teddy's still pink hair. He got up from the table, marched down to where she was sitting and as calmly ad he could manage, asked her for a quick chat. She obliged and they ended up in an empty classroom.
"What the hell was that for?" he exclaimed as soon as the door closed.
"I warned you to stop calling me Vicky!"
"So you made Lily send a howler to me?"
"Well, honestly you had it coming. You know how much I hate being called 'Icky-Vicky'."
They glared at each other and it seemed as neither one would back down. Then Victoire erupted in a fit of giggles.
"Honestly your face though! It was bloody fantastic!" Victoire said in between giggles. Teddy's hair flared into pink for a bit before it settled back to turquoise and he too started to chuckle.
"Stop saying bloody!" he scolded half-heartedly.
"I will if you stop calling me Vicky."
"Only if you stop calling me Theodore."
"I think we have a deal Lupin" she said grinning. She stuck out her hand and they shook on it.