Disclaimer: I don't own any of J.K. Rowling's creations.
Sirius Black heard the distinct sound of the Floo network. "Harry, mummy's home," Lily's voice rang through the Potters' residence in Godric's Hollow.
Dammit, they're home early. Sirius was counting on their meeting with Dumbledore to last longer.
"Relax, Lils," he heard James come to his defense. "I'm sure Padfoot took perfectly good care of him." Good old, Prongs. Always got my back.
"Yeah?" He heard the disbelief in Lily's tone. How dare she have such little faith in me? I'm a great babysitter! "Why does your face say otherwise?"
Well...then... never mind, Prongs, you little traitor.
As soon he heard dainty footsteps rushing up the stairs, Sirius quickly walked out of Harry's nursery, shutting the door carefully behind him. He came face to face with the suspicious redhead. "Hello there, Lily, darling," he gave her a charming smile. "How was your night?"
"What did you do to my son?" Lily did not look amused. Her arms were crossed; wand in her hand.
"Why Lilypad," Sirius feigned hurt. "I don't understand your complete lack of faith in me. Why would mini Jamie not be okay?" He blinked innocently.
Lily quirked an eyebrow and tried to reach behind him to open the door. He quickly blocked the doorknob.
"Sirius…" her voice was low, containing a hint of warning. Note to self, Lily Potter loses all sense of humour when it comes to her son.
"Okay, okay," Sirius raised his hands in surrender. "But first, answer this."
Lily sighed impatiently. "What?"
"Hypothetically speaking…" Sirius grinned sheepishly. "What are the risks of human transfiguration on a baby…?"
Lily's eyes widened in shock. "Y-you..you…you," she sputtered, raising her wand.
"YOU TRANSFIGURED MY 3-MONTH-OLD SON?" James Potter rushed up the stairs, his hand holding a crushed chocolate cupcake with orange and black frosting. Hey… they better have brought me some. There's nothing sweet in this entire bloody house!
"SIRIUS!" the couple was in complete sync. "EXPLAIN!"
"There's a perfectly logical explanation," Sirius let out an awkward laugh. "I was trying to transform his clothes into a pumpkin costume…and then I got distracted…"
"You turned our son into a pumpkin…?" Lily slowly inhaled, probably mentally listing a number of things she could turn him into.
Sirius just laughed nervously. Lily and James shoved him out of the way and burst into the nursery. Sirius waited in the hall with a smirk.
"Padfoot! I'm going to frigging kill you!" His best mate shouted.
And that was his cue. Sirius gracefully slid into the nursery, releasing a burst of black and orange streamers from his wand. "TRICK OR TREAT!"
James threw the cupcake at his face. "You little twit…" His best friend's glasses were skewed and his eye was twitching.
The Potters were standing by their son's crib. Baby Harry was dressed adorably in a pumpkin costume; the rest of the nursery was also decorated in Halloween themes. Lily, too relieved to see Harry was safe, appeared to have forgotten her anger. She even started playing with the paper bats flying around. Or so he thought. "Explain," she turned to him with a glare. Even James had his arms crossed.
"It's Halloween," Sirius said in all seriousness. "If you don't leave me a treat, you get tricked!"