Hello dev...
your game looks great that's why before playing I want to confirm that there is no ntr or cheating because I avoid those
Here's the non-developer's take
The game includes NTR elements only if you choose to engage with them; it's entirely optional, and it's implied that whether or not you do so will lead to a different ending—though since there isn't an ending yet, it doesn't really matter at this point.
But rest assured, if you want to live with Rosette and remain faithful to her, you can do so