I've edited short stories for my buddies before, probably why I started reading.
Not the type of story I was expecting, it definitely seems like a screen play more than anything.
Grammar, like people pointed out before, is a bit sloppy in parts but thats easy to fix. Conversation is believable, not really forced and doesn't sound fake.
Biggest thing I'd suggest working on, is fleshing out the people/characters more. Think of novels you read, and characteristics that you want your character's to have - do they talk with their hands? How do they stand? Try and work in some mannerisms and descriptions of what people do while they're walking - no one has a conversation standing with their arms at the side. Also try to work in inflection, emotion of the people talking - like with Kianna breaking up with Lamonte, was she angry/pissed/sad?
Do you have any favourite authors? Couldn't hurt to re-read some of their stuff to get an idea of how they describe their characters - whether its a short story or screen play, you've got to help your readers picture who the people are, how they act etc. You can probably do that more effectively than listing off their height and weight.
Anyway, my 2 cents. The last Chapter makes me think this will turn into a porno.
At least throw in some girl-on-girl, eh?