Why "even"? red bikini was the sexier one right? And no panties is clearly "slutty", so I would expect that to lead to the panties even if asked to put something down.
I thought thats just happening either way, I would like to know, does she actually put something on before she goes down if those choices were always made to be the "less" slutty one?
I don't see alternate renders in the images folder, so I guess she was always going to go down in panties regardless of choices.
I dunno how you can't find those renders, but if the wife is not corrupted enough, she will listen to your suggestion and give Marcus the pillow while wearing pants (modest). I am not sure of the exact requirements to get that version, but I imagine
you have to "resist" all or most of the NTS options from the start - at least, that's how I managed to get it.
As for how to get the NTR version of the scene (where the wife ignores you and goes down in panties), I think you have to choose a certain amount of NTS choices, i.e. she needs to be corrupted enough.
From what I could tell peering into the code of the game, there is a variable that tracks a certain number value, but the code is a "mess" from my perspective, every single choice in the game is simply named "option<X>", so it's really hard to tell which corresponds to which choice. This dev certainly has a method to their madness.
But the clothed scene exists.