"Hello, Professor!" Snape opened his eyes and found that he was tied to a chair in the Potions classroom and wearing a frilly lemon yellow dress, he had a splitting headache, and to top it off, Harry-bloody-Potter was sitting on the desk in front of him, beaming. This was definitely not good.
"Potter! What are you doing here?" he snarled, trying his best to sound intimidating, "and what am I wearing?"
"Why, it's a dress, sir. I thought that was obvious!" said Harry cheerfully.
"I KNOW that, I want to know why I'm wearing it!"
"Well, do you remember going to Professor Dumbledore's office last night?"
"Yes…."
"And he offered you a lemon drop?"
"Mmm…"
"And that two years ago, you blackmailed him to get a pay raise and he said he'd get you back?"
"Yes- OH MY GOD! WHAT DID THAT [censored DO TO ME!" yelled Snape, totally losing his cool.
"He spiked the lemon drop with firewhiskey, got you into the dress, and made you dance around the school. He Modified your memory, by the way, so you wouldn't know it was him."
"CUT ME LOOSE!" Snape screamed, losing all sense of reason.
"Okay," said Harry, muttering a spell under his breath that made the ropes binding Snape fall to the floor. As soon as he did it, Snape flew to his feet, out the door, and down the hallway, screeching, "ALBUS PERCIVAL WULFRIC BRIAN DUMBLEDORE! I'M GOING TO KILL YOU!"
A moment after, Ron Weasley pulled off the Invisibility Cloak with a flourish, popping into visibility next to the door to the Potions classroom brandishing a small camera and grinning evilly.
"Got two hundred pictures, mate," he said to Harry, who had come out of the classroom to watch his worst teacher run through the school in a dress.
"Excellent. Think we should tell him that we just Stunned him and stuck him in one of Hermione's dresses?" "Naah."