A nice Midwestern lady in a nowhere town will dress nicely and do her hair for lunch at the Radisson. She may not have been dolled herself up to flirt, but rather to feel pretty, presentable for a class outfit like the Rad, with a soupçon of sexual curiosity, but only if you insist.
A hugely pregnant woman might be happy of a few compliments from a an old high school friend but mostly she can’t wait to get home to Norm and tell him all about it. It might liven up their sex life - now and for years to come. She’s friendly and kindhearted - and she likes people. But she loves Norm.
That expectation of fidelity in marriage may have at one time been a feature of life in the flyover states. You folk out West don’t get those breezes. Why would anybody assume Marge was out seeing if she could scout up new talent unless they’d never seen or experienced fidelity in any relationship?
When she inserts a bit of cop voice at the very end of telling him to get back on his own side of the table, the movie fan gets a thrill followed by suspension of disbelief at her charm in the moments that follow. We see her telling herself what to do next and dealing with dismay at how this reunion is turning out, since it’s now clear there’s something seriously wrong. And lo, she may have been a fool for agreeing to meet him. Women often have to top up their life skills to keep up with their professional ones.
Marge is the practical Midwesterner through and through. She’d most likely been hoping to try the food at the Radisson. Big, substantial, carb and gravy laden stick to your ribs comfort food goes down well in those cold, cold winters.