That is probably the most disturbing, creepiest, chilling short story I've read in the past month. I LOVE IT! ^^
Read the story now
Anyways, the way you write it gives a dark atmosphere that you don't even notice and the sense of forboding carries through before the big reveal.
How the Coffee Boy affects the family is very clear and the transformation is slightly detailed and horrifying, leaving the result to the reader's imagination and leaving a subtle hint of the unknown.
You probably wrote this light-hearted and for fun, but this is a great work! It really should be published in a modern teen short story contest or publishing :D
Now, onto to read your other three stories. I loved it! Also, the foreshadowing you added in "Someday you'll be able to do that," is such a big hint and clue now that I look back at it!
And Dylan's claims to 'want to be like him' (Coffee Boy).
The only thing that irked me is that, everytime I read the protagonist's name, it reminded me of Dylan. From Latin class. ><