Adventure Time with Fionna and Cake: Gumball's Envy.

Adventure Time with Fionna and Cake: Gumball's Envy. 
A new year had started in the Land of Ooo. It was also Fionna's Sweet 16 Birthday. She was in her Birthday Gown, whilst Cake was decorating the Tree Fort. Fionna sluggishly sat down on the old couch, sighing. She examined the room with her sapphire blue eyes. There was no Birthday Cake. Just a round table and some banners. The feline had returned from decorating the Tree Fort. She smiled at her sister, as if she was saying "Happy Birthday". 
"Happy Birthday, girl". 
"Thanks. But this place needs more pizzaz". 
"Pizzaz? It looks math quite enough!"
"No. I mean ... where's the cake?"
"I asked Gumball if he could make it".
"You what?! I thought you were!"
"Nah. I'm too busy". 
Fionna was annoyed with the fact Prince Gumball was making the cake. Nobody else was in the fort apart from them. That also annoyed Fionna. Cake had written out invitations, but nobody arrived. A few minutes later, Marshall Lee floats slowly through the open window. 
"Happy Birthday, man". 
"Hey Marshall!"
"How's it going so far?"
"Not good". 
"No? How about a little song?"
"Uh...okay. I like your songs".
Marshall Lee blushed back in response. He got out his Axe-Guitar and started to play a song. He named it "Birthday Girl".
Oooh Fionna
Today's the day
When you shine
It's your birthday
Have fun
Eat some cake
Sing karaoke
And dance with me
Fionna stood up and grabbed Marshall's hands. They danced slowly as the vampire sang. 
Oooh Fionna
Today's your day
To shine
So have a great day
My baby girl
They both gazed into eachother's eyes. The two of them were nearly closing in on eachother. Gumball eventually arrives with his cake. The cake was taller than him, and it had loads of detail on it. As he saw the two falling in love, he drops the cake then runs out the fort. Fionna swiftly drops Marshall Lee onto the floor.
"GUMBALL!"
"Ha ha! What a loser!"
Fionna runs outside the fort, leaving Cake and Marshall behind. She follow's Gumball's every move. She then ends up in Gumball's room. He was sobbing violently on his bed, sinking deeper into the mattress. Fionna sits beside him and starts to almost feel bad for him. 
"Hey, Gumball. What's the matter?"
"I saw you and Marshall together.."
"Oh. Right".
"I love you, Fionna". 
"W--What?"
"I do". 
Gumball sits up on his bed and closes in on Fionna. She wraps her arms around the poor guy and wipes his tears away. Today was a bit of a tragic day for the prince. I mean ... no cake, Marshall stole Fionna and she's changed quite a lot. 
"I'm sorry about this".
"No, no, no. It's okay, dude!"
"No it's not".
"Well ... Marshall is my guy friend. You're not. You're different".
"Different?"
"Yeah. You're not just a chum".
"O--Oh my ... really?"
"Yeah".
"Oh glob ..."