Being the boy who lived and the semi chosen one had both it's perks and downsides, at least In Harry's experience. for example, while he got away with WAY more then he should of, he was also expected to be beyond certain things, such as say.. Using his cloak to sneak into other peoples rooms and spy on them/mess with them while they were asleep. 
But that was exactly what he was doing tonight, as he crept though the halls of Hogwarts and made his way to Draco's room. To be fair, Harry wouldn't be doing this if not for the fact that Draco, Crab and Goyle hadn't of replaced have of the chocolate in the chocolate pudding desert treat that Gryffindor had won in a house challenge with chocolate ex-lax, which had left half of the Gryffindor's stuck on the potty, and those were the lucky ones who had made it to the loo on time.
Hence, Harry had every intent on sneaking into Draco's room and extracting a little revenge, Since despite Draco all but taking credit for the act, no one could prove anything and Snape had swooped in to protect his nephew.
whether he'd get blackmail info or just make Draco foul his bed up or both, Harry wasn't sure, though little did the boy who lived know that whatever he was expecting to find and all of his plans, would be going out the window in no time.

Draco whirled and narrowed his eyes as the door to his room opened slightly, stomping over and slamming it shut, his eyes looking around all paranoid for a moment.
Of course his door DID have a bad habit of opening itself, but since this was the last private room available and it was take the bad door or share a room with others, Draco had swallowed his pride and taken it.
"you'd think since we can fire off bleeding death rays.. we'd be able to fix a fucking door and make it stick." he muttered, even as he took out his wand. 
Just because his door was semi broken didn't make Draco relax too much when potter had a invisibly cloak and was known to go roaming at night. Add in what Draco had done and well, of course he expected a visitor. 
God, just thinking about the sight of all those stupid wanna be hero's, self righteous knights wanna be's crying out and holding the seat of their pants as they soiled himself, double so for that one first year student who cried out for mummy.. 
Draco lowered his wand as the front of his black and green flannel PJ bottom's tented out and he bit his lip. 
"..Potter if your in here.. I'm about to crank one out and go to bed.. if you watch that's the sorta thing that will get you booted out, scar or no scar.." Draco said, and waited, looking around the room. 
With nothing happening he gave a sign of relief, there was no way Potter would of stayed, which meant that Draco got to do the one thing he ALWAYS did when he got this horny. 
walking over to his bed and reaching under it, Draco pulled out a green duffle back and unzipped it with one hand, tugging down his PJ bottoms with the other and then reaching in the bag and starting to pull out his favorite outfit: a stupid thick green cloth nappy, a clear pair of locking plastic pants and a bib, setting up the nappy and showing off his less then stellar boyhood which was locked up in a cute small cock cage, naturally green. 

Harry almost took off, not wanting to watch Draco crank one out but then his attention was drawn as Draco fished out the duffle bag, watching with delight as he took note of the cock cage and then doing a double take and almost dropping his cloak as he saw Draco's baby outfit.
'No. Bloody. Way. Draco's a nappy boy!' Harry thought, biting down on his tounge to keep from talking out loud, but Draco was off in his own little world now, talking to himself.
"Nggggh Pwease daddy, I wanna be a big boy and make a big boy mess! no diapies!" he lisped, squirming and picturing a dominant older boy was in front of him, squirming and giving a pout.
"Heh, Sorry baby Draco, but the only messes you get to make are baby ones. I'm sure if we keep your cute little wand locked up long enough, making a smelly nappy will make you go 'pew pew' in your nappies. or at least, being bounced in my lap. Now are you gonna be a good boy and lay down or do I need to spank you?" Draco ALSO said, taking on both roles since he believed himself to be alone. 
"Nooo daddy! No spankies! I'ma good boy!" Draco whined, plopping his butt down on the cloth diaper and starting to pull it up to diaper himself.
'bloody git.. he's not using any baby powder!' Harry thought, then had to fight down a snicker as he realized that no, Draco HADN'T been affected by a batch of itching powder last month.. the big baby had been suffering from diaper rash!
Harry also almost laughed out loud again, Draco had his tounge sticking out the side of his mouth as he pinned himself snuggly and then tugged the plastic pants on hopping in place and tugging them up to get them over the bulky cloth nappy and making his pampered butt look even bigger as he got them on.
trying the bib around his neck (Which announced him as daddies little blue balled baby) Draco plopped his nappied butt on the Floor, reaching under the bed and tugging out a stuffie of a snake and hugging it. 
"Daddy, can you tell me and slithers a story? the one about the poor blue balled big baby who was too cute to be allowed ta grow up?" Draco coo'ed, hugging the stuffie and squirming.
Harry had seen all he could without speaking up and removed his cloak, Speaking up behind Draco before the big baby could talk in his daddy voice. 
"Of course I can tell you a story little guy, but let's get the big nappy baby tucked into bed first." Harry said, grinning ear to ear as Draco turned around, eyes wide and blushing badly.
"P-Potter!?!" He squeaked out, a muffled fart being heard and he found himself unable to scramble for his wand, or move at all. not because of a spell but just frozen in shame and fear.
"no silly baby, not Potter." Harry said, coming over and helping Draco to his feet, and unable to keep himself from fondling and patting Draco's slick padded butt. "It's DADDY now." 
"I.. but.. you.." Draco mewed, really wishing he hadn't of had such a big dinner, that he had used the loo before retiring to his room for the night (though of course he had been planning on going to bed smelly) and wishing he'd double checked his room. "Ok..."
"Ok what?" Harry asked, grinning like a git.
"Ok.. Daddy." 

With Draco tucked in nice and tight (and Harry having found the keys for both the plastic pants AND the cock lock) Harry made sure Draco was snuggling 'slithers' nice and tight and then picked up a text book, hamming it up that it was a story book. 
"Once upon a time, there was a little blond prince who went out of his way to be a total brat to everyone and everyone." Harry started, pausing as a muffled fart was heard but then he went on, pretending he hadn't heard it or any of the others that followed even as Draco started to squirm as cramps were building up in his tummy tum. 
"The people hated the little brat prince but no one was brave enough to confront him, and the king was too busy too deal with him, even when the prince would walk around the castle and load his pants and giggle like a naughty toddler, loving the fact others had to smell. him. Of course, this could only go on for SO long before the prince went and filled his pants in front of a handsome and dashing knight who knew JUST what the smelly little prince needed!" Harry paused and smirked. "Draco, slither's..do either of YOU know what the brat prince needed?" he asked in a sing song tone.
"Guhh..He..he needed someone to understand it was just a silly thing and forget about it and let the prince stop all on his own?" Draco tried, a wet fart coming out and he knew it wasn't going to be long now. 
"Heh.. Good thing your cute little cute, not much in the brain's department going on. No, the Knight knew what the brat prince needed was a poopie pants spanking and then being put in the thickest, most babyish diaper he could find and then paraded around so that all the villagers could point and laugh at the big baby, who was helpless in a stroller. Oh how the prince whined and begged for mercy, but despite how adorable his pleading was, the knight knew that the prince needed a real daddy, and a life time of nappies and baby treatment. The king agreed too and sentence the brat prince to be nothing more then the knights baby slave forever and ever, and despite how much the prince cried, his wand showed how happy he was! The end." Harry finished, one hand holding the book and the other rubbing the front of Draco's diapers though the blanket, the big baby sucking on his thumb and scrunching up his face as he made a mess in his nappy. 
"heh, not the mess I thought you'd make from the story, but then again, your just a little baby aren't you?" Harry said, wrinkling his nose at the smell that filled the room.
Harry got up to leave, making sure a light stayed on as Draco's 'nightlight' and paused as Draco, barely awake from the effort of the mess and ironically the act of being put to bed by a strong daddy meekly called out.
"Uh..Daddy.. Diapie change? I poopie." He mewed, eyes drooping.
"Heh, I know you are, but I think a night in a smelly nappy will do you a world of good. I'll be back to change you in the morning before breakfast." Harry promised and blew a kiss to the blond, who had conked out and missed what harry added in a low voice.
"If I don't sleep in." 

The (smelly) end!