This was based on a tumblr prompt in which Ron's patronus starts... um... humping Hermione's leg at a DA meeting.

Era: OOTP
Rating: T

Bad Terrier!

Fred and George play a little prank on Ron at a DA meeting.

"Ron, can you conjure your patronus again? I can't figure out how to do it," Fred called to Ron from across the Room of Requirement.

Ron's face lit up into a smug expression when he heard Fred's request.

"Aww, Ickle Ronniekins is so excited to show us how to do something," whispered George. "I'm so proud of him."

Fred laughed. "Let him soak it up while he can. Remember the spell?"

"Yup. You?"

"Got it."

The twins exchanged a mischievous look as Ron made his way over toward them.

"Sure can! Expecto Patronum!"

A silver terrier burst from Ron's wand and began trotting around the room. Fred had to admit that he was impressed- it was quite the feat of magic for a fifteen year old. But they couldn't let Ron get too smug about it. The twins muttered their incantations quietly, while subtly pointing their wands toward Ron's terrier. Ron was too focused to notice any suspicious activity.

"Perfect," muttered Fred. The twins watched as Ron's terrier sauntered from person to person happily wagging his tail and nuzzling legs on the way. Then Ron's patronus stopped at Hermione, who was equally focused on her own silvery otter that swam around the room, unaware of the hologram at her feet.

"And here we go!" The twins stood back and grinned excitedly as the silver terrier wrapped his front paws around Hermione's leg and began grinding against it. "Oh my god, we're geniuses," said George.

"Hermione, ew!" Ginny was pointing at Hermione's leg with an expression of disgust. Ron's expression turned from one of focus, to horror. Hermione's otter disappeared as she whipped her head around to the terrier, losing focus on her own patronus, and she attempted to kick the terrier off of her leg.

"Gross! Ron! Make it stop!"

Fred and George sniggered when Ron's terrier slowly dissipated as he lowered his wand. "Hermione, I didn't mean to-"

"Ron, why would you do that! That's disgusting," said Ginny.

At this point, the incident had earned the attention of the entire room. "I didn't do it! I didn't even know that patronuses could do that!" he stammered.

"Ron, what was the memory you used?" laughed Seamus. "Giving your terrier some ideas?" Fred and George chuckled.

"Ron, looks like you should focus just a little bit more on that patronus. Keep it together man," said Zacharias to another round of laughs.

"You're gross, Ron!" said Ginny.

"Shut up everyone!" said Ron to the crowd. "Hermione, I'm sorry, I don't know why that happened."

"It's fine," said Hermione. "Let's just keep practicing." She still looked angry and embarrassed when she tried to conjure up her otter again, without success.

Ron, whose face was burning scarlett, shoved his wand back into his pocket. Clearly he had no intentions of practicing more tonight.

"I feel kind of bad," said George. "We embarrassed him in front of the girl he fancies."

"It'll toughen him up. He needs it," responded Fred. "Plus, everyone else deserves a bit of a laugh these days."

"Whatever you say," said George with a smile.

Later that evening...

Fred and George returned to the common room after their DA meeting and paused in the portrait hole when they realized the room was empty, save for Ron and Hermione.

"Shhh!" Fred sent an arm in front of his brother to halt him, and the two backed up behind the wall to hide. After their little prank on Ron's patronus at the DA meeting, they were extra curious to overhear the conversation he was having with Hermione.

"Do you have your extendable ear with you?" asked George.

"Of course, I never go anywhere without it," said Fred as he reached into his pocket for the listening device.

"Ron, it's fine, just don't do it again, ok?" Hermione was sitting on an armchair by the fire, a textbook open in her lap. Ron sat across from her, with a pleading look on his face.

"You have to know I didn't do it on purpose! I have no idea how that even happened!"

"I don't care! Just own up to it, and promise not to do it again, ok? It was so embarrassing and gross!" said Hermione.

Ron's face was burning scarlett. "Embarrassing for you? Imagine how I feel! Everyone was laughing at me!"

"Maybe you should choose different memories, if the only ones you currently have cause your patronus to… hump people," she said the last part hesitantly, scrunching up her face in disgust.

"Well you don't have to worry anymore, Hermione," said Ron in exasperation. "I doubt I'll ever be able to conjure one again."

Then Ron caught George's eye when he slipped into sight to adjust the placement of the extendable ear.

"Hey! What are you doing?" Ron stood up angrily. "Are you eavesdropping on us?"

Fred and George exchanged a look and a nod. At first, Ron's anger and embarrassment was amusing to them, but they knew they had taken it too far.

"Sorry little brother," said George, stepping in from the portrait hole. "We have something to tell you."

"Get on with it then," said Ron with a clenched jaw. Hermione had returned to her book, seemingly interested in observing a row between the Weasley brothers.

"It was us," said Fred. "We made your patronus do that. It was a prank."

Ron's expression fell to relief, then quickly turned back to anger. "What? How could you humiliate me like that?"

"Well Ron," said George. "It's technically our job as your big brothers, but this time we took it too far."

"Yep," agreed Fred. "It happens sometimes," he added with a shrug. "The only way to find the line is to cross it occasionally. Right George?"

"Right," George replied with a nod. "And we're really sorry Ron."

Ron scowled at them. "Well, you should apologize to Hermione as well. You humiliated her too." Ron turned around to get Hermione's attention, but she was now watching the twins with a look of amusement on her face.

"You did that?" she asked. "How?"

Fred and George exchanged another questioning glance. "What do you mean?"

"How did you make Ron's patronus do that? That's really advanced magic!" She narrowed her eyes at them. "I don't condone it, as a prefect, but I'd be lying if I said it wasn't impressive…"

Fred and George beamed at her. Ron, however, looked at her like she had betrayed him. "Wait… now you liked it?"

"No!" said Hermione quickly. "It was disgusting! But I honestly don't know how they did it. I thought it happened on it's own, but now that I know they manipulated it...That's pretty amazing!"

"Sorry Granger, we're going to keep that little bit of magic to ourselves," said George smugly.

Hermione shrugged. "Imagine what you could do if you applied those brains to more important, less gross things. Seriously."

"Oh, we'll go far. Don't you worry about us Hermione," said Fred. "So you two aren't going to wave your prefect authority over us? Give us detention or anything?" He narrowed his eyes and asked cautiously, 'Write to our mother?"

Hermione shook her head. "Only if you do it again."

"Ron?"

Ron turned his scowl onto the twins. "I won't write Mum, but I will get you back."

"Oooooh, George! Ickle Ronniekins is out for revenge," joked Fred as Ron's face turned pink in both embarrassment and anger.

"Fred, you know we deserve it."

"That's true," shrugged Fred.

With another exchange of glances, the boys continued through the common room toward the boys' dorm. "Goodnight Ron! Hermione! We can't wait to see what kind of revenge you cook up for us," and they proceeded up the staircase, leaving Ron glaring after them.