Character Analysis
Gloria might seem like nothing more than an obstacle set in Don's way on the road sobriety (a red shell, in Mario Kart terms), but this perception sells her character short. As we learn more about her, we get a few tiny glimpses of the real person who's hurt by Don's drunken antics.
As Gloria would say, it's obvs that she's crazy about Don from the moment we meet here. Although Don is more than willing to flirt (a little too willing for a guy with a girlfriend, if you ask us), it's clear that he doesn't take this younger woman's advances too seriously. That is further evidenced when he accidentally asks her on a date, which is a suggestion she immediately jumps on.
Naturally, he stands her up. That should've been expected. What wasn't expected, however, is that Don would show up at her apartment the next day asking for cash. (The nerve.)
Though Gloria scoffs at this at first, she eventually gives in after Don exploits her feelings for him:
DON: Could you let me have some money?
GLORIA: Say, you out of your mind? Don't be ridic. [...]
[Don kisses her.]
[...]
GLORIA: How much money?
Is there anything you won't do for booze, Don? Either way, our compassion for Gloria's character increases tenfold after we see Don manipulate her just as he manipulates anyone who loves him.