That photo of Martha is quite worrying. She's dripping wet. To me, she's always been there to fill the gap while MC prepares the groundwork for the family unit.
It doesn't look like lubricant to me; it's the color of semen and flows like semen, and it has the same amount of semen. Skin cream or lubricant, besides having a larger volume, flows differently.
This type of content should be better prepared and optional. Once the player sees it, there's no turning back, not shoved in their face to test their reaction. They've tried it before, and it never works, especially when the developer promises not to use NTR or NTS.
I hope the developer isn't thinking about MC just watching Miuky become a woman, but rather that it's what leads to her becoming a woman.