Good Evening (Or whatever time of day you are reading this).
Please allow me to set the scene for you.

This takes place during Order of the Phoenix when they are residing in the Blacks not-so-humble home.
They have been there for one week and still have about a month until school.
Before Hemoine left her parents gave her a gift.
A television (that she shrunk to make it more portable).
She also brought her wii, some games and a few movies.
Then she gets the fantastic idea to introduce Ginny to Just dance.

"Hermione, can I come in?" Ginny asked well knocking on the door.
"Sure."
When Ginny entered the room she was greeted by Hermione, who was sitting on her bed in her and Ginny's room reading a book.
"Haven't you already read that book? Like twice?" Ginny asked sitting next to her.
"Yes. But there really isn't much to do now, is there?" Hermione said setting her book down and raising an eyebrow.
They sighed. There really wasn't much to do.
Harry and Ron were in their room across the hall talking and playing with Hedwig.
Fred and George were in their room experimenting.
As they sat there in silence thinking of things to try and make the hours go by just a little faster Hemione remembered he shrunken T.V.
"Do you want to dance?" She turned and looked at Ginny.
"Why not." A smile was spreading on both of their faces.
Hermione opened her trunk and pulled out her small T.V. and wii and the game just dance.
She made them large and set everything up.
Ginny watched in awe.
"You should show my dad, he would be fascinated by this."
"I haven't even turned it on yet." Hermione said with a small laugh.
She turned it on and put in the game.
Ginny laughed as they skipped through trying to find a song.
The finally settled on 'California Gurls' by Katy Perry.
"So, What do you do?" Ginny asked exitedly.
"So you hold your remote like this-" She said holding up hers "-Then you follow the moves on the bottom corner of the screen"

[Snoop Dogg:]
Greetings loved ones
Let's take a journey

[Katy:]
I know a place
Where the grass is really greener
Warm, wet and wild
There must be something in the water
Sippin' gin and juice
Laying underneath the palm trees
The boys
Break their necks
Try'na to creep a little sneak peek
(at us)

You could travel the world
But nothing comes close
To the golden coast
Once you party with us
You'll be falling in love
Oooooh Oh Oooooh

California girls
We're unforgettable
Daisy Dukes
Bikinis on top
Sun-kissed skin
So hot
We'll melt your popsicle
Oooooh Oh Oooooh

California girls
We're undeniable
Fine, fresh, fierce
We got it on lock
West coast represent
Now put your hands up
Oooooh Oh Oooooh

Sex on the beach
We don't mind sand in our stilettoes
We freak
In my jeep
Snoop Doggy Dogg on the stereo

You could travel the world
But nothing comes close
To the golden coast
Once you party with us
You'll be falling in love
Oooooh Oh Oooooh

California girls
We're unforgettable
Daisy Dukes
Bikinis on top
Sun-kissed skin
So hot
We'll melt your popsicle
Oooooh Oh Oooooh

California girls
We're undeniable
Fine, fresh, fierce
We got it on lock
West coast represent
Now put your hands up
Oooooh Oh Oooooh

California girls
We're unforgettable
Daisy Dukes
Bikinis on top
Sun-kissed skin
So hot
We'll melt your popsicle
Oooooh Oh Oooooh

California girls
We're undeniable
Fine, fresh, fierce
We got it on lock
West coast represent
(West coast, west coast)
Now put your hands up
Oooooh Oh Oooooh

Their dance came to the end and both girls finished with a pose.
"Woo!"
"Encore!"
"Bravo!"
"No, Fred, you are saying it wrong, it's Brava!"
The pair spun around on their heels now aware of their surprise audience.
Fred and George were standing their with huge smiles that stretched across their face.
"What are you doing here!?" Ginny yelled punching George(a little to hard to be playful)on the shoulder
"We heard music and came to check it out." Fred said placing his hand on Ginnys shoulder.
"Well, sense you are here, it is your turn." Hemione said handing her remote to George.
He accepted and Fred grabbed Ginny's.
"Ginny, I am going down stairs to get us some water, will you explain to them how to play." she said then wispered "Make them do Beautiful Liar"
"Sure thing."
As she explained how to do it, Hermione ran down the hall to fetch Ron and Harry.
Hermione burst into the room laughing.
"Are you okay!?" Ron asked running up to her.
"Fred-George-Belly dancing-" Was all she was able to get out between laughing.
Ron and Harry looked back and forth between Hermione (Who was know laying on the floor clutching her sides) and each other.
She quickly stood up and drug the boys down the hall.
About half way there they heard the music.
They snuck into the room and sure enough Fred and George were in the middle of the room Belly Dancing to Shakira.
Ron and Harry put their hands over their mouths as to not laugh and disturb the twins.
Finally Ron lost it and almost fell over laughing.
Fred laughed and George glared at Hermione.
"Come on! You didn't tell us we were going to have an audience." George exclaimed.
"You guys looked fabulous!" Harry exclaimed.
"Even we could do better then that!" Ron said.
"Bring. It. On!" Fred said.
All four boys grabbed a remote and Hermione picked a song.
The boys started dancing and Harry was in the lead.
about a minute into their Brittney Spears song the door flung open and Sirius walked in followed by the parents.
The stopped dead in their tracks, stunned by the sight of the boys rocking out to Brittney.
Their song ended and they did their last pose.
"HA! I finally beat you two! I am the Champion now Fred!" Harry yelled.
Sirius couldn't stand it any longer. He burst out laughing.
Harry walked over calmly and grabbed his wrist, sliding the remote on and tightening it.
"Your turn" Harry said with a wicked smile.
"No no no. I don't think so."
"Oh come on, it is fun!" Fred said.
He looked around the room.
Hermione turned on a song for him.
Barbra Streisand.
Everyone was in tears by the end of it.
"Alright. Let's go get some snacks." said walking down stairs with everyone following her.