MC will be the one who takes her virginity and nobody else. You may influence things that happens in the story but you will not be allowed to change their personality. MC loves his daughter and will try to do what he believes is best for her. If people have a problem with that premise then this game is not for them.
Changing the path where you deny her to the point she starts flirting with danger with Gregory from being a drugged rape sequence that cuts off right before the rape to a path where he is able to corrupt her over a couple of days into having sex with him and then cutting to the game over screen after the sex scene wouldn't create two different games.
It would also fit with the premise of your decisions needing to go toward a specific path which would be the best path for her in the long run, but it would also give some of the people who are rolling their eyes at the game what they want. A bad end/game over that isn't you pick something and then next screen is game over. Or the ones that actually want to see Gregory succeed.
And with the darker paths you 'might' do toward the end of the game they wouldn't be any different. Bad ends that quickly lead to a game over, only instead of it happening earlier in the game its happening right at the end.
In this case it isn't really an issue of people having a problem with the premise. Its a problem with being railroaded into it and the few decisions that you do give us to stray from it are hollow because its a few dozen lines of story, maybe one or two CGs, and then the game over screen.
I get at this point you'd have to go back and change the text and image version, so I understand why you wouldn't want to waste dev time redoing something that was done in the text version a year ago. I'm mostly pointing out a way that scene could've been done different so that later bad end paths could be fleshed out better to feel like there is more.