This is a drabble filled for Drabble-A-Thon in the Chubwinchesters community in LiveJournal. I accidentally submitted the prompt as an anonymous ... so .. here the story is re-posted in the fan fiction network;D
I hope it's okay?
Ejoy!

Request: Fat!Sam

Dean is pulled out of class by a teacher to help calm down Sam who is so fat that he's gotten stuck somewhere (desk, slide on playground, around a corner, etc.)

"Excuse me, is there a Dean Winchester in here?".

Dean looked up from the math test he was taking and saw a teacher with curly, brown hair sticking her head into class. Her eyes flickered nervously around. Dean´s teacher Mrs. Adams turned her head.

"Yes, he is right.. "

"What's wrong with Sammy?". Dean interrupted her and stood up.

"Well...". The brown haired teacher said. "You better come see for yourself".

Dean followed her out the door, feeling the eyes of his classmates in his back. Dean felt himself going into big-brother mood. If someone had hurt Sam they would soon regret it.

They walked towards the playground outside.

"I honestly don't know how it happened, and your brother seems to be too upset to tell us". The teacher told Dean as the approached the slide. It was one of those big ones with towers and ropes and climbing walls. A small black tunnel connected the two towers. Another teacher was standing near the slide looking slightly stressed out. At first Dean couldn't see his brother. Then he realized why.

"He is stuck in the tunnel isn't he?"

"It seems like it". The teacher answered. "How is it going Charles?". She asked the male teacher as they reached the slide.

"Pretty bad. He only calls out for Dean and that construction is not made for grown ups so I can't get him out". He said while making a I-give-up gesture with his hands.

"I found the brother, maybe he can help?". Dean rolled his eyes. What was it with grown ups and talking like he weren't even there. He was fourteen. Not a child. He could hear a tiny sound of sobbing coming from the tunnel. Sam.

"Sammy? Don't worry, I'm coming okay". Dean said loud enough for Sam to hear him. The sobbing seemed to stop.

"...Dean?". Sam´s voice was quiet and he had clearly been crying for some time.

Dean crawled up in one of the towers and found the entrance where Sam's head was. His little brother was stuck with his arms ahead of him and his belly and back pressed against the tight space.

Tears ran down his chubby cheeks and his eyes were red and puffed from crying.
"Hey Sammy, are you okay?". Dean asked with a voice full of worry. Sam's head bobbed up and down a little, but he wouldn't look his big brother in the eyes.

"Sam. Look at me.. What happened?". Dean asked in a soft voice. Apparently it was all Sam needed.

"Dean.. Dean, I'm sorry...Declan dared me to go from one tower to the other, and I thought I could do it, but he was right, I couldnt... Dean, they all laughed and said I was... I was.. too fat to play with them". Another tear rolled down his brother's cheek. "..I'm stuck..".

Dean felt a wave of anger run through him. Sure his little brother had gained weight lately. Okay, a lot if Dean was honest. He was pretty sure they weighted the same, and he was more than a head taller than Sam. His little brother had gone from chubby to downright fat, but that was no reason for anyone to pick on him like that.

Dean gave Sam a reassuring smile.

"Don't worry Sammy. I'm gonna get you out".
As if those were magic words Sam visibly relaxed and tried to stop himself from sobbing. Dean reached into the tunnel and put his hands on Sam's chunky arms.

"Alright, when I say now, you suck it in, okay?".
Sam nodded.

"One. . Now! ". He pulled back as hard as he could. Dean could feel his brother slide slightly towards him before he was stuck again.

"It's not working". Sam looked at him with panic in his eyes. He was clearly about to hyperventilate.

"Sammy. Listen to me okay". A nod. "We are going to get you out, but you have to calm down. If you relax, you will slide right out. I promise". Dean assured him. "Let's try it again".
He grabbed Sam by the arms and pulled back as hard as he could. First nothing happened, but suddenly Sam glided towards him and with a POP he had his little brother in his arms. Sam hugged him tightly and Dean felt the soft body against him shiver as Sam sobbed against his shoulder.

"It's okay, Sammy. You're okay".