One thing I love about my husband....he definitely has the manners (and general upstanding-ness) when it comes to going out on the town and bar-side decorum. If he treats you to a drink (or more), it's because he's feeling generous, you are attractive (I suspect some Colorado cowgirls have benefited from "falling" into this category), you look interesting or appear to be enjoying yourself, or you've been tagged by him as deserving (maybe you're an underdog).
I personally feel that all of these are more-than-good reasons to buy a drink, a dinner or conversely, engage in light (or not) conversation with the person buying. It's a little contract....of manners and of a very particular type of social engagement.
One thing my husband would never do; misrepresent his marital status or that of his company. In terms of conversation, he'd never talk too much about himself and he listens carefully when you are speaking. He'd also not suggest that his or your collective behavior were untoward because it never would be.
It's too bad that someone's momma or daddy didn't learn 'im on this type of etiquette, but I'm so pleased my husband would nevah make the boorish mistakes practiced on me by a Birmingham, Alabama resident last night (though his "nephew" proved charming and seemed to "get it").
(unfinished painting of) horace acrylic on strathmore pending