A/N: Actually a side-story in a longer fic, if you enjoyed this, be sure to read the other one when it comes out.

Takes place when Harry is around 6 months old or so.

"Padfoot! Padfoot! Padfoot!" Harry, only three and a half months old, tugged playfully on his Godfather's long black hair.

"Harry! Harry! Harry!" Sirius replied, tickling Harry's sides as he did so.

Harry's dad, James, mock scowled at the pair. "Don't you think it's time Harry learnt a new word, Sirius?"

Sirius looked from his contemplation of Harry's toes, a puzzled look on his face. "Why?" Padfoot is all he'll ever need. When he needs help, he'll just have to yell -PADFOOT! And he'll have it."

James sighed at his best friend's silliness. "Come one, Sirius. Let's at least try!"

"Try what?" Lily asked as she walked into the room, arm in arm with Remus.

"Prongs wants to teach Harry new words," Sirius mumbled absently. He was busy making dark purple sparks dance, to Harry's delight. Harry cooed at the sparks, clapped his hands, and caused bright green lights to dance from the tips.

"We've been trying to teach him, James. He's rather attached to Padfoot though. Both the word and the person," Remus remarked, more than slightly amused.

James groaned. "Come on? Please? I wanna hear him say `Daddy' and `Mommy'."

Sirius and Lily looked at him. "But he does say Mommy," Lily protested. "Don't you, Harry?"

Harry looked at her and grinned. "Mommy?" He stretched out his arms for her to grab.

James' mouth dropped open with shock. "How come you didn't tell me?!" James demanded.

Lily shook her head. "I thought you knew, darling. He started calling me Mommy two days after he called Sirius `Padfoot'."

"And he started calling me `Moony' the day aft4er that," Remus said, innocent with a mischievous glint in his eye.

"Right Harry?"

"Moony!" Harry yelled in agreement.

"Well, why won't he call me Daddy?!"

It was obvious that James was losing patience, and quite possibly, sanity.

Very quietly, Harry murmured, "Daddy?"

James turned and looked at his son, utter amazement and happiness apparent on his face. In two steps, he'd arrived at Harry's side and had picked the baby up.

"You said Daddy! You said Daddy!"

"Daddy," Harry said agreeably. "Daddy Padfoot."

James stopped bouncing his son and looked at him, eyes wide. "Wh- What?"

"Daddy Padfoot!" Harry reached his arms out to Sirius, who stood behind James with a bemused look on his face.

"Well, " Sirius remarked as he plucked a giggling Harry from James' limp arms, "I guess you're stuck with being Uncle Prongs."

"Uncle Prongs!" Harry said from within the circle of Sirius' arms.

James sat down, well and truly shocked. "It isn't enough that Harry's first word has to be Padfoot. He's got to start calling him THAT as well!"

As Sirius passed Remus, Harry giggling in his arms and a smirk on his face, Remus asked under his breath, "How long did it take to set that up?"

Sirius replied, also under his breath. "About a week. Don't clue James in."