Young Writers Society

"Ah, you're here!" A familiar face appeared behind the doorway. "Took you long enough!"
"Mathew! Don't be rude!" his mother scolded. "Let them in!" We were led into the warm household, instantly greeted by folk with Christmas cheer. "I love your sweater!" Mrs. Schwartzman commented, making me blush ruby red.
Mr. Schwartzman and my dad were in a conversation about their children with Mathew just within earshot. "Please don't say anything embarrassing, Dad," I pleaded under my breath.
Rather than linger in the den, I wandered about the house avoiding the mistletoe and large groups of people. My eyes scanned the decorations and the content smiles people had on their faces. The Schwartzmans really knew how to throw a party. Suddenly, Mathew bumped into me, wrecking my train of thought. "Oops! I am so sorry!"
I gave him a small smile, assuring him I was fine. Smiling back, he asked, "Hey. Do you want to play chess?" Moments later we were seated at a table with a chess board in front of us. That's when Mathew started making excuses. "Now I haven't played in three weeks so I'm rusty, and the only opponent available was my sister, Maddi and she's not too good at chess." I let him ramble on while I got busy with my strategy. Deciding on a tactic, I moved a pawn forward. Mathew stopped jabbering and stared at me. "It's on," he said. Fourteen-year-old Mathew v.s. twelve-year-old me. Who will win? I had yet to find out.
I set my pieces in a defensive position, while Mathew used various traps and attacked with occasional jabs, similar to a snake. Finally, I couldn't hold out any longer, and Mathew took my other knight. He now had both of my knights, one rook, a bishop, and five pawns. I held in captivity five pawns, both rooks, a bishop, and a knight. The game was near its end. "You want to surrender?" Mathew inquired, a smug smile spreading across his face.
"Never," I retorted. No way I was letting him beat me. Surveying the board, I spotted a golden opportunity. Quickly sliding my bishop across the board, I rammed into Mathew's queen. He looked up at me, then down at the chess board, not believing what I had just accomplished. I gave him a I-can't-believe-you-were-that-stupid look then placed the queen with my other captured inventory. Victory.
Dad yelled my name somewhere else in the house, signaling my departure. Mathew let out an unsatisfied groan and banged his fist on the table, making the pieces bounce up and scatter all over the floor. We stood up and shook hands. "You've been a worthy opponent." Mathew commented, leading me to the door.
Smiling, I said,"You were pretty good too."
He beamed and promised, "I'll be better next time you just wait and see." With that final statement, my family and I clambered into our car and drove into the night. My mind was still wavering on Mathew and the challenge he had given me.

Hello, Muffin!

I love the mood you set with the Christmas party. You do a wonderful job of showing us how your MC feels at the party rather than telling us she is uncomfortable. Nice.

General points:
1)This was a little hard to read because you didn't separate the dialogue from the rest of the paragraph. Although I knew exactly who was talking, it is still preferred that dialogue be on a different line from the preceding paragraph.
2)You got a little dialogue-tag-happy. If you don't need a tag, leave it off. It helps the flow of your writing.

Nitpicks/Things I particularly liked:(Do you like my Christmas colour scheme, here? )

"Took you long enough!", he said.

This would be one example of leaving off the tag. But if you are really attached to "he said," get rid of the comma. If you end a quotation with an exclamation point, you don't need a comma. However, you do still make the first word of the tag lower case like you did. Same goes for question marks.

"Mathew! Don't be rude!",his mom scolded.

This takes care of that other dialogue tag for you. Again, no comma.

Mr.Schwartzman and my dad

Space after "Mr."

"Please don't say anything embarrassing dad,"

Whenever you call a family member by their title, it needs to be capitalized. So "Dad" here should be capitalized. If there is a possessive adjective in front of it (my, our, your, their, etc.) then it's lower case. Also, Dad is an appositive, so you need a comma before his name.

I wandered about the house avoiding the mistletoe and large groups of people.

You got me to laugh with this one.

"Oops! I am so sorry!", he apologized.

Please fire this tag. With budget cuts and everything, it would definitely be in your interest to let him go. Sorry as I am for the fella, but his job is covered by the dialogue.

That's when Mathew started making excuses.

Typical.

Now I haven't played in three weeks so I'm rusty, and the only opponent available was my sister, Maddi and she's not too good at chess.

Whoa! Is that all one sentence? Normally, I would try to break up this run-on, but I sort of like it this way. It lets the reader picture the sputtering boy trying to cover himself before his loses to (gasp) a girl!

"It's on.",

Okay. If a piece of dialogue would normally end in a period, you always end substitute the period for a comma if you have a dialogue tag. (Ex: "I wish it would rain," she sighed.) If you start a new sentence after the dialogue, then you use a period. (Ex: "I wish it would rain." She stared at the cloudless sky and sighed.) I probably didn't explain that very well, so if you have any questions, let me know, and I'll try to do better.

I held in captivity

Nice phrasing.

Mathew let out an unsatisfied groan and banged his fist on the table, making the piecies bounce up and scatter all over the floor.

Tut, tut. Anger management.

Overall, I thought this was a nice, light-hearted story. My critiques were mainly structural and can easily be fixed. I like your characters and how they work together. Nicely done.
Best wishes,
-Sea-

Ya i suck at grammar and all that.

Psh. Once you understand how it works, it's an easy thing to fix.

Nice story.

I don't see any problems as such in your story .. But that is not saying much as my grammar sucks !

But I liked your characters and admire your writing style.

You have written some particularly nice sentences. My personal favorites are -

Rather than linger in the den, I wandered about the house avoiding the mistletoe and large groups of people.

Suddenly, Mathew bumped into me, wrecking my train of thought.

Dad yelled my name somewhere else in the house, signaling my departure.

I agree with Searria H. You need to separate the dialogues from the rest of your paragraph and leave some of the dialogue tags.

Other than that great story

Do keep writing ! !

Good Job and Good Luck !