I presume it got changed "for the plot", if that's actually the case.
Lame, if you ask me.
Sorry if my comment was confusing, there ARE sex scenes, just very few of them. there's a good amount of nsfw animations, like foreplay stuff, but very few penetration sex scenes, you should check it out, it's a really good game!
also, if there weren't sex scenes, it would still be labeled "porn game" due to the amount of nudity, and foreplay, games tend to do that before they release more sex scenes.