I just picked up the game, and I'm enjoying it in general, I have some qualms here and there, but overall an enjoyable experience.
Now, about the Sophia thing. I think I'm a more moderate kind of guy when it comes to scenes with LI and other people. Some in this webside I have seen defend that if two LIs get involved with each other, without MC present, it is NTR, and some also think that lesbian sex is NTR if it is between a LI and a girl that isn't a LI. So we have various levels of radicalism in the subject. I disagree that my first example would be NTR, and I'm conflicted about the second, so, that is why I consider myself more moderate on the subject. I don't think that any and all interactions between LIs and any other character that isn't the MC is NTR, like I have seen some people defend in this forum on other instances.
All that said. The husband scene sucks. I don't like NTR in my games, but I do enjoy Netori (hypocritical, I know), so the idea of taking another man's girl and humiliating him, it is quite apealing, and even though the scenes serve to further humiliate the husband with his small prick, they still depict him on top of a girl that I was invested in, so even for me, who are not as radical as some people here, it was still a no no. Honestly, I don't want to tell you how to run your game, but I strongly recommend you take it out. It will just put off people from the very demographic you are trying to appeal to.
There are several other ways you can reach the same story beat without having the scene. Maybe another form of abuse, verbal or physical. Maybe, because they are broke, he neglects her, and the last man she fucked in recent times was the MC, and then she starts to crave more and more sex, but since the husband won't give it to her, she ends up on the arms of MC again.
If you really want to keep a scene with the husband, you could make it so that he goes to have sex with her, but his dick is so small that she isn't even interested, and then, because of all the stress, he goes soft without them even touching each other. That last one would have to test the waters, I don't know how people feel about a man being naked in the general vicinity of a LI, even if nothing happens, to me it would be fine, but for some more radical people it might also be a no no, who knows.