The first time I read this, I enjoyed your concept and the economy of the storytelling. I then reread it to get a better handle on it to provide feedback and found myself stumbling on some details. So… my overall comment is: a good concept, competently written. Needs attention to details.

Some of the details you might want to look at:

This is possibly pedantic (c’mon, why not?): is the clock in the opening image digital or analogue? I assume it’s analogue because further along you refer to seconds tick away… If that’s the case you might want to indicate the time as: quarter-to-twelve (drop a.m. – we see sliver of sunlight). This, I think, fits the ambience of the bar better.

Descriptions
You might be better served if you delete or abbreviate some descriptions. For example:
Maybe cut:
-- Perhaps the only sign of life in this benighted shit-hole.
-- wishing the evening rush would come. ...and go.
-- Intentionally.
-- or so he doesn’t appear.
-- filled with... who knows?
-- Our Man, the Suit, (keep one or the other)

Not sure about these:
-- But regardless, he’s a Suit. A middle-aged Suit. (Nice feel, but probably redundant).
-- eerily (I don’t get this - distracting).

Dialogue
-- Homeless Man’s dialogue, I think, comes across as contrived, and this appears to be inconsistent: I don’t plan on spending the rest of my life drinking away my sorrows with you, buddy. Then he says: Same time tomorrow?
-- This confused me: I’m not the one to be givin’ public speeches-- to strangers at that! Isn’t Teen the Man’s nephew? (Unk; Hey Auntie…)

Sluglines
-- These may be technically justifiable (dunno for sure), but you might want to consider alternatives to lighten the load, especially for a short of five pages. Can probably lose at least some of the Another Angle (Later) without any danger. In the context, they’re sounding directorial, and get in the way.
-- Not sure about this: FADE TO BLACK TEEN (V.O.) How well do you know your husband? Personally, I like your idea of the V.O. black screen. Just not sure how well it will play. Aw, heck, go for it!

I like the way you wrote the transition to the present, and your ambiguous ending: Will Teen blab or not?

Good work that will benefit from some tidying up.

As a Film Noir script, this would be very good. I understood everything well enough and I could totally imagine it being filmed in black and white Sin City style.

I think the biggest problem with the script is the secret. It's not big enough. The guy drinks with a homeless guy and sleeps with a prostitute, I was expecting bigger. You had more pages to play with, I think this could have been so much better with much more at stake if the teen tells all to the woman.

Writing was great. Very visual, I could picture everything. Some things could be cut in your descriptions but we're all guilty of that at some point. I also noticed you missed a question mark on your very first line of dialogue and again on the bottom of page two. I feared the worst at that point but I'm glad I was proved wrong.

Overall, I'd be very interested to see this filmed in black and white. I was impressed when I read this, then I read the comments and I can't say I agree with the majority of them. Maybe it's just personal taste, I don't know.

A teen turns down a Trans-Am?  I thought this was supposed to be a drama, not science fiction.

I can't say this was necessarily bad, but I'm definately not going to say it was exactly good, either.

One thing...  it needs a lot of work.  There should never be that many typo's in a 5 pager.  That's laziness.

I did like some of the descriptions, though.  In fact...

Quoted from Two Beers A HOMELESS MAN, about fifty yards up, sorts through a SHOPPING CART filled with... who knows?

I love that description in particular.  It says everything we need to know about him.

So, this has it's good points, but it also has it's bad points.  I didn't like it.  But I didn't hate it.  It needs a good, a very good, rewrite though.