Character Clues
Character Analysis
Family Life
Um, we probably don't need to say too much about this, do we? We already know Eddie and May have a seriously messed up relationship from the get-go, but when we find out they're siblings, that increases the skin crawl factor threefold (at least).
The fact that they continue to participate in an unhealthy incestuous relationship tells us truckloads about where they're at mentally. We don't necessarily know why (although their creepy bigamist father might be a big clue), but we know there's something seriously amiss they are willing—nay, unable to resist!—participating in those kinds of shenanigans.
Clothing
The stage directions give us a sense of how these characters dress, which in turn tells us a bit about them. Take Eddie's clothes, for example. According to the stage directions that open the play, he's wearing "muddy, broken-down cowboy boots with silver gaffer's tape wrapped around them at the toe and instep, well-worn, faded, dirty jeans that smell like horse sweat. Brown western shirt with snaps." Also, "A pair of spurs dangles from his belt." So, you get a sense that he's a real cowboy who doesn't mind getting dirty and isn't terribly vain about his appearance—well, maybe he is, but he's not vain about being particularly clean.
We know he's pretty, er, dirty in other ways, so he has an appearance to match.
Speech and Dialogue
Since the entire play is dialogue, this is an easy one—pretty much everything we know about the characters comes from what they say. One interesting example comes when we finally learn who the Old Man is—both with respect to Eddie and May, and just as a person.
Having just been told that his ex-wife (well, one of them) killed herself after he deserted her, he seemingly tries to get out of taking any blame by saying he didn't know anything about it:
THE OLD MAN: Nobody told me any a' that. I was left completely in the dark.
EDDIE: You were gone. (559-560)
He had been upset that May was even telling the story, and now that it's out, he seems completely unwilling to admit responsibility for hurting his families—by just saying, "Oh, yeah, I didn't know." Pretty slimy, if you ask us. As Eddie points out, he was gone, so of course he didn't know. Sorry, Old Man, but desertion isn't exactly the best excuse for not knowing something.
Anyway, it's a smallish moment, but it really shows us what a snake the Old Man is, trying to wriggle away from the truth and then, when it's out, implying that the fact that he ran away should excuse him from responsibility for anything since he was living in the bliss of ignorance.