Let me try to explain this differently. In writing, there are things called plot lines. Now when we choose to romance SH, that main romance and its content only (without anything optional), becomes plot line A.
Now the optional porn stuff doesn't even become plot line B because it doesn't actually have any plot. Plot requires cause and effect; a beginning and an end. The optional stuff does not have this. It has no effect on you or the relationship. The ending of the game proves this. Therefore it can't actually be considered a part of the story at all. No plot, no story.
It's just something there for entertainment, but has no actual value.
