Another thing that came to my mind just now is something I mentioned in the OG NTRaholic thread. Have the character deal not just "physical dmg", but also "emotional dmg" as well. Prove you're a more interesting, self-assured and proactive guy. This would help setting a natural attraction to you and improving your image to her, despite your assaults. It would definetly shift to a more romance type game, but that would benefit the NTR part, I think.
Perhaps creating a new bar, other than the lewd one. One related to shame/charisma, where the higher it is, the less likely she would give you opportunity to advance on her or would resist and end the H-scene quickly. Whereas a lower shame/charisma bar would make her more inclined to have sex or even unlock new positions or places to do it.
I don't know. I keep thinking stupid stuff, but something like Self-Defense NTR Dojo did with "Going to the movies" event. Like, for an example, have the MC and the husband compete in a strongman game, win and make her impressed, or use the money from your job, not buy items, but to buy expensive gifts to her(for her supposedly good job cleaning the house) that the husband can't give and maker her feel adored. And with each progress, as you do this "going out with the couple", you notice she starts wearing more revealing clothes(to get you attention), she starts setting up events(like, tripping off while using her skirt) and make you see her panties or even the lack of..., leading ultimately to a sex in public. Something like that I would very much like to see in future games of this new innovating genre.