Dude, you are really lucky, you know it? Now you in awesomegreatepic game thread. Its simple: You should add to story 2 more words in post.
I'm starting:
In Equestria

there was

In Equestria there was a pony

In Equestria there was a pony with a

In Equestria there was a pony with an elegant mane,
I hope it's ok to change a's and an's? :o

In Equestria there was a pony with an elegant mane,her name

In Equestria there was a pony with an elegant mane,her name was Cupcakealicious

In Equestria there was a pony with an elegant mane,her name was Cupcakealicious. She loved

In Equestria there was a pony with an elegant mane,her name was Cupcakealicious. She loved her fluffy

In Equestria there was a pony with an elegant mane,her name was Cupcakealicious. She loved her fluffy brown bunny