7. Foot
It was a lazy day in the home of Sirius Black and Harry Potter. Sirius was stretched out on the couch reading a book, while Harry sat in an armchair watching TV. Harry was painfully bored, but too lazy to do anything about it. He needed to find something to keep himself amused without having to get out of his chair. He scanned the room for possible cures for boredom that were within arm's reach. There was a Rubik's cube, but those were too frustrating. There was an old copy of the Daily Prophet, but he had already read it. Harry briefly considered changing the channel to something interesting, but the remote was too far away. Damn.
Then he saw it: a stray feather lying on the ground, only inches away from Sirius' bare feet. Harry laughed evilly in his head. Sirius's greatest weakness was that he was horribly ticklish. Harry had found his source of entertainment.
Or at least, he thought he had. The feather was too far away for him to reach. Harry sighed in frustration.
Then he remembered that he was a wizard. Duh.
Harry pulled out his wand and positioned it in such a way that Sirius wouldn't be able to see it. "Wingardium leviosa!" he whispered. The feather rose slowly from the ground. Harry moved his wand and positioned the feather so that it just barely brushed Sirius' foot. Sirius jumped and pulled back his foot. He looked at Harry, but the boy wizard was clearly watching TV. Sirius shrugged and returned to his original position on the couch and continued to read.
A few minutes later, Sirius felt the tickling sensation again, only this time it was stronger. Again, Sirius looked to his godson, but again, Harry was staring blankly at the TV. He looked over to his godfather. "You okay, Sirius?" he asked.
"Huh? Oh, yeah...I'm fine..."
Harry nodded and returned his attention to the TV. Sirius shook his head vigorously. He figured he must finally be going crazy; it was the only possible explanation for the phantom tickling. He sighed and returned to his book yet again.
Sure enough, the tickling soon returned, far more intensely than before. He let out a yelp and pulled his foot back. He looked up to see Harry trying his best to hold back his laughter.
"Why you little!" Sirius yelled and pounced on Harry, who was now in hysterics.
And thus, a tickle fight like no other ensued.