I know about that. The two paths seem to be the same, but one is different from the other. I just did a summary, but perhaps a function for Max to sabotage Eric's relationship with his sisters could be implemented to keep him away from them, thus avoiding the NTR if the player didn't want to see it.
So, this is a story and the story has to make a little more sense. Eric has to play the role of antagonist, the two paths follow a logic of what the player will want. I just made a short summary, but the story would be different, I also made the two paths become similar, because nobody likes to play a game that you have to keep grinding. So, what I wanted to say is that if you wanted to be friends with Eric you would see X content, Eric would share Ann and Alice (maybe Kira too?). If you would choose to be Eric's enemy, you would have Ann, Alice, Kira and Lisa. But of course, since you're at war with the character, there will be ways to sabotage him.
The MC will not lose the girls to him, you have to remember that this is a porn game, and I already said that the MC will kick him out of the house, because I don't see much point in staying with Eric for a long time in the game. You'll see the same porn content with another character for a while, how bad is it? Yes, there are people who don't like it. But why then did put the character in the game? because it would make sense in the story. It doesn't make sense that Max doesn't have anyone to hinder him, it's like the other games I've played, MC easy life, all the girls kneel for MC, MC has no effort, MC needs to grind in the relationship... this is so understanding that you look for something more engaging and can't find it. Anyway, I think Eric's content has to be a good content and not so long, because keeping the character for longer ends up becoming tiring and boring, because I honestly hate the grinding function. But I also see your point of view, and I agree with some things, maybe the enemy path would be better not to contain NTR, but of course the player would have to work at it, sabotaging Eric's relationship with his sisters. Anyway, talking about Kira, I think she is a key character in the game. Many ideas can be implemented for her, and I still prefer her to play the role of corrupting the girls in the house and helping Max. In order for the story to make more sense, she will have to ally herself with Max because Eric is blackmailing and fucking her (in the original game she even likes to be fucked by him, but things could change in this new game, let's say she would think Eric an asshole, you know?), and in this, she discovers that Max is a wicked boy and the two team up to kick Eric out of the house and she will help Max with his wishes. (The story of the original Big Brother everyone knows)
