Piecing it Together

First off, the guy isn't convincing. Most guys aren't self concious, they tend to be watching other things. He wouldn't notice his sweat, unless it was an obstacle to something, like keeping a hold of his suitcase. We also look at physical characteristics for hints of their character.

Also, guys aren't traditionally super materialistic. So, styles are generally foreign to us. Your character is seeing "American Eagle" when he should be seeing jeans. The male mind doesn't like to waste energy if it doesn't have to and "American Eagle" is pretty complicated vs. jeans. These traits are more common for women.

You can throw some of that out if I'm meant to hate him because it is working really well if that is the case.

Also, watch out for run on sentences and starting sentences with "and". Run on sentences are easy to detect because they talk about two different subjects without going to another sentence. They also go on forever. Split them up into two sentences. "And" isn't a good way to start a sentence because it is a conjunction, it should only be used only in dialog, and only immediately after another sentence of dialog. Example:
"So Arzor is starting to destroy Teddy Bears."
"And Dinosaurs."
[/example]

Um, yeah...guys are materialistic where I live. They don't think jeans before they think Hollister or American Eagle. It's all about brand name to a lot of guys here, because that's what will make them get looked at. I enjoyed the story, and the several perspectives. Perhaps the insant-chemistry between the cousins was a bit...well...instant, but it was nothing too bad. Just run it through a quick grammar check...and by that, I mean re-read it slowly, and maybe read it backwards once. I caught a few things.

Overall, I enjoyed it. Four.

Materialistic isn't accurate because we are materialistic.

However, we tend to fall more on the functional side of materialism, where females tend to fall more towards the fashionable side.

When I walk into the room with some of my friends, they don't immediately start checking my clothing labels. That's just retarded. Of course, they and I are a little eccentric, so perhaps it isn't as general a case as it is (or it is possible that the guys over at your place have a lost their blue collar charm, but I couldn't say.)

"I’ve never even met these people and I’m supposed high school living at their place? "
It's not good to start a story with a very noticeable error! You're missing a word or two in between 'supposed' and 'high school.'

Be wary of your appositives and how you place them in a sentence:
" Thinking about unpacking gets my mind, if only for a moment, off of the subject at hand."
The "if only for a moment," should be placed at the end. It is grammatically correct as it stands, but it's easier to read if you move it to the end.

I really like your writing style, and you definitely grabbed my attention with it. It's witty, short, to the point, and funny. Something like:
"I line my eyes darkly and apply the dark eye shadow I prefer. Mascara. Blush. Chapstick.
I’m good to go. "
Says so much more than using up a couple paragraphs to describe which one she might prefer, and the reasons behind that choice.

Which leads me into, you're good at descriptions. There are some things, such as what Griffin pointed out with guys, that seem unrealistic, but you do a pretty good job with them overall.

All in all, I really liked this.