Birthday gift from Grandma

When I opened my 18th birthday present from my grandma, my face dropped. She had gotten me a 'Gym Shark' vest. I'm not sure where she got the impression that this was something that I wanted or needed, after all I barely weighed 125lbs, I was stick thin and had never been in a gym in my life. To make matters worse, the vest itself was way to big, it would fall straight off me if I was to wear it.

I didn't want to make my grandma upset, so I quickly put a smile on my face and thanked her for the gift.

"Well.." she said, "go and try it on" she smiled.

I didn't want to be rude, she was my grandma after all, so I slowly took the vest and walked out of the living room and into my bedroom. "This is so stupid" I said to myself as I took my t-shirt of and held the vest up in front of me, I could tell it was made for someone three times my size, but with a sigh I threw it on and tried to adjust the straps so that they would stay on my small shoulders.

There seemed to me a warmth coming from the vest itself, It was weird. I looked at myself in the mirror as I slid the strap up again on my shoulder. Did they seem... wider? No, it couldn't be. I looked closer at my reflection, did my arms always look that big? and did my chest always buff out that much?

I watched in shock and awe as my reflection grew and expanded with muscles.Growing larger and larger until I didn't have to adjust the straps any more, they could now more than stay on by themselves, in fact, if I keep growing I might even snap them. My once bonny and skinny body was now muscular, my pecs barely being held in by the vest, my arms now huge masses of muscle compared to what I could once grip on hand completely around, and I actually have abs aswell.

I'm not sure what my grandma has done, but this is certainly the best present I have ever had, and I am sorry for ever doubting her.