Glad to help!
Some great thoughts and questions in this piece!
“Baby It’s Cold Outside” was just playing at my inlaws’ on Christmas, and I listened carefully because I’d heard for years how it was actually a coercive dude trying to turn a no into a yes. But my take was the woman in the song is fully doing the “We shouldn’t” based on external factors, just like you wrote here. So there’s a lot of sexiness in imagining they both totally want it.
I mean, that song is totally a product of unequal gender expectations, as he’s not worried people will call him a slut. And if it was real life, I would want him to be more straight-up in asking her what she wanted rather than just trying to convince her, BUT in fantasy-land, yeah, “we shouldn’t” can be super-hot for all parties involved.