I AM CANADIAN. I AM IN NO WAY BRITISH; THEREFORE THIS DOES NOT SOUND BRITISH WHAT SO EVER.
"Crap, crap, crap, Lily's going to hex me." muttered James Potter as he poked gentle index fingers into the sofa cushions.
Sirius Black grinned from the doorframe he was leaning against. He threw his hands up in sarcastic disbelief, "You had one job, Potter. Put the baby down for a nap; And now you've gone and—"
"Oh, sod off, Black. You could help you know." James said while glaring up at his best mate, the angry glare thinly veiling the panic beneath.
Sirius flicked his hands at James in a 'not my problem' manner, before disappearing into the kitchen. At the sound of multiple crashes escaping from the kitchen, James jumped up from where he'd been kneeling beside the sofa, waving his hands underneath in search of an invisible object.
"Oi! What the bloody hell do you think you're doing?" shouted James; the man was a menace in a wide open field.
"Looking for your kettle!" yelled Sirius back, appearing around the doorframe with Lily's favourite teapot. "Found the cups and pot, but not the kettle. Blimey your cupboards are big. Undetectable Extension Charm?
James signed, going back to his search for Harry, "If you use that set, Lily will hex you too. The normal set is in the third cupboard on the right wall, and the kettles on the stove, you prat."
"She'll be hexing me anyways, seeing as you'll make this all my fault." he replied, voice gravelly with irritation. Sirius rolled his eyes at the back of James head and slid back into the kitchen, his second disappearance was followed by another crash and a shout of, "DAMNABLE CAT!"
The grey fluff of fur they called Pepper bolted from the kitchen and rocketed up the stairs, tail between her legs.
"Lucky you, Pep. You can hide from her." he murmured after the cat. He got up from the sitting area and shuffled across the room, careful not to move too fast incase his toddler was curled up on the floor. After checking the arm chair seat again thoroughly, he collapsed into the high backed chair and rubbed his temples, panic setting in.
Technically this was all Sirius' fault.
Lily had gone out to do her regular Sunday shopping and had given James one simple task, or so he thought. He was supposed to put Harry down for a nap at two o'clock, and then he was permitted to do as he pleased.
Finding Harry had taken almost fifteen minutes, and that was when he was fully visible. The little guy could get into so many different places, it was nearly impossible for James to find him immediately. How Lily managed to find him so easily was beyond him.
He'd almost given up and used a Summoning Charm when he heard a giggle from the corner of the room. He'd spun around and found Harry sitting there in his blue onesie, black hair sticking out every which way. He sighed and grabbed the giggling toddler, and carried him out to the sofa, where it was easier to calm him down by rocking him.
However, calming Harry down enough to sleep proved just as difficult as finding him in the first place. After 20 minutes of shushing and rocking, Harry had just drifted into the land of unconsciousness when Sirius arrived and rapped smartly on the door, before pushing it open grandly and waltzing in. A murderous glare from James, as well as the little tyke being rocked back and forth, stopped Sirius in his tracks. James slowly got up off the sofa and turned his back on Sirius, heading to Harry's room, careful not to wake him.
"C'mon Jamesy, we've got to get through the game before Lily gets back!" Sirius hissed from the doorway of Harry's nursery.
"Black, I have better things to do than play Quidditch with your swarmy arse." James hissed back to him.
"Like what?"
"Put my son to sleep!" James spat hotly.
A giggled erupted from the toddler as James settled him into the low lying crib.
Sirius let out a barking laugh, "Dammit Jamesy, look what you've done." He wandered over to the crib and stuck his fingers in Harry's face, wriggling them and laughing when Harry batted at them.
James groaned and pulled Harry back out from the crib and carried him back out to the sitting room, where he began rocking the squirmy baby again, shushing and whispering, while Sirius made faces at his god son over James' shoulder.
"Not helping, Sirius." complained James, smacking behind him without looking. Sirius laughed again and moved around the sofa to crash down beside James.
"Just wrap him in your cloak again James, he always falls straight asleep in the cloak." Sirius said hands folded behind his head.
"I don't have it with me. Lily took it to town to clean it."
"What about The Cloak?" Sirius asked, a mischievous grin spreading across his face.
"He's hard enough to find when he's visible, now you want me to wrap him up in an invisibility cloak?"
"Yes. Just leave his head out; he won't move much when he's asleep." Sirius reasoned.
Whatever prompted James to agree to this plan would later be sought out and killed violently. Leaving Harry with Sirius, he raced to the bedroom and pulled the cloak out from the trunk at the foot of the bed. Running back, he quickly wrapped Harry up in the clingy, smooth fabric. Most of his child disappeared instantly, while his head and wild black hair still stuck out. Harry gave a sleepy yawn and fell asleep almost as fast as his tiny body had vanished.
Noting they still had an hour and a half before Lily came back, James decided he'd be back inside before to put Harry to bed properly, and left the bundled up baby sleeping among the pillows on the sofa.
"After you, Prongs. Hope you're ready for a fair bashing." boasted Sirius, gesturing to the door.
"I'm sorry Padfoot, who in this room is one, absolutely gorgeous, and two, the best seeker Gryffindor's ever had?" teased James, running out the door ahead of his best friend.
"Stupid. Stupid. Stupid." James muttered to himself. He was all but banging his head on the wall. Last time he did something this stupid, Lily kicked him out for 10 days, and only gave in after some serious woman-worship. Singing roses, a bass quartet, tiny fireworks that spelled out messages of sweet nothings in the windows, the whole shebang.
But that when he had locked Pepper outside and she'd run away for the night. Oh, she came back the next day, screeching her head off, but Lily wouldn't let James back in because it was his fault. This wasn't the cat he lost, but their son. She'd never let him back in the house after this.
He sighed wearily and got up from the chair, still shuffling across the floor incase he missed the spot his child was. As he headed up the stairs to collect the things he'd need when Lily kicked him out, he called to Sirius,
"I'm gonna go get my things. Looks like I'll be staying at yours for awhile."
"You really think she'll—?" Sirius voice sounded from the kitchen.
"Kick me out for losing her baby boy? Yes." said James resolutely, continuing up the stairs and past the spare bedroom where Pepper was asleep on the double bed. He might as well face the fact he'd never see his son or wife again and—hold on a minute.
He doubled back to the spare room and glanced in again. Unless he was going crazy, Pepper had sprouted and unusual growth on her left hind leg. A very small unusual growth that was jet black and spike-y looking. Venturing closer, he noticed his wand was lying on the ground instead of on the nightstand where it should have been. Taking that as a bad sign, he crept closer to the sleeping cat, and gently prodded the black spikes on her leg.
Hair. The jet black spikes were hair. He prodded the hair again, and a little face appeared, smiling up at him. James snatched the rest of the cloak off his son and bellowed,
"SIRIUS, I FOUND HIM. GET YOUR ARSE UP HERE."
A whoop and a crash told him Sirius was on his way up. It was only when he looked back at Harry he realized something was wrong. Harry was tiny usually; stick thin, even for a baby. But right now he was too tiny. Tiny enough to fit in James' palm.
Sirius skidded around the corner to the spare room beaming,
"Looks like you don't have to break out the woman—Oh… Oh dear."
The grin faded as he noticed just how small his god son had gotten. Both their eyes travelled from the tiny baby to James' wand, lying on this ground. James looked close to tears, so Sirius bent over and picked up the wand. Teething marks were scratched into the mahogany wood near both the base and tip.
"However, on second thought, you may want to pull out the woman-worship in full force." Sirius said quietly, looking up and down the wands length.
"We could just reverse the spell." James tried.
"Remember when Peter fell asleep in Charms second year and his wand did the same thing to him? And what happened when we tried to reverse it?" Sirius reminded him.
James flinched at the memory. Peter had swelled up to over 5 times his normal size, and had to be in the hospital wing for more than a week before he was properly deflated by Madam Pomfrey. He wasn't about to try that on his son; Lily wouldn't just kick him out; she'd flat out murder him.
That was when the door clicked and unlocked; Lily was home. The men panicked immediately, not being able to come up with a decent story fast enough, and James was called downstairs to help put away the shopping. Sirius went down first, James trailing behind him, Harry concealed behind his back.
"Sirius, lovely to see you." Lily said, setting the shopping down on the table.
Sirius grunted in reply and stood woodenly beside James. Ever the hawk, Lily knew something was wrong and her eyes narrowed to slits.
"What have you—." she started, before being cut off by Sirius, who yelled,
"It's all his fault! I'm innocent!" and disapperated on the spot, leaving James to deal with his angry wife.
He cleared his throat before saying quickly, "I put him down for his nap, and when he came back, he'd gotten out of his crib and was sleeping in the spare room with Pep. And my wand was on the floor, he'd been chewing on it and…"
He decided to skip the part including the invisibility cloak and the fact he'd left Harry on the sofa to sleep, shrinking their child was bad enough. He brought his hands out from behind his back and offered Lily a glance of their tiny son. Her eyes widened in shock, but she didn't say anything yet. James closed his eyes, and tensed, waiting for the blow to come, for her to scream and cry and shout abuse at the top of her lungs.
But it never came. Instead he felt a soft pressure against his cheek, and when he squinted to look at her beneath his eyelashes, she was wearing a smile and her eyes were bright again.
"James, you fool." she laughed as she took Harry from him.
He dropped his hands to his sides, confused. Where was the angry Lily he'd been expecting all this time? Was she hiding under the cheerful Lily? The one that had currently turned her back on him, and was fishing around for something in the drawer on the left wall of the kitchen.
She eventually pulled out a small vial of a dark purple liquid and unstoppered it with one hand. She tipped the vial slowly towards Harry's tiny mouth and poured a few drops in as he yawned. Closing the vial again, they both watched as Harry shimmered for a moment, and then returned to his normal size. Lily smarty dropped the vial back in the drawer and closed it with her hip, walking back to James and handing Harry to him before going back to put away the shopping.
"I… Wait what? Why aren't you mad? Not that I mind, just… What?" James asked, thoroughly confused again.
"My mum warned me about babies teething on anything and everything they could find. Eventually I knew one of our wands would end up in his mouth, so I popped down to the Apothecary and bought a spell reversing potion for this exact reason. I know about the stunt you pulled in second year, and I didn't want a balloon for a son."
James was relieved. He brought his now normal-sized toddler closer to his chest and held him there, smiling down at him for their good fortune.
"Besides," she said, smirking at James from across the room, "I bet it's all Sirius' fault."
AN2: So I think 2 of my headcannons came out in this. One, James is slightly afraid of Lily; two, Sirius is clumsy as all hell.