The dev constantly blows his load with the sex scenes, giving them the opposite effect they should be having.
Dev, when making a sex scene in a VN you don't make them long fuckfests with the two parties engaging in every position from start to finish.
You need to spread them out so the readers can build up anticipation for what's to happen next.
There's a reason why in most VN's characters usually only engage in rudimentary acts for the first few scenes then build up to intercourse over the course of the story. This gives us readers breathing room, and allows buildup.
If the characters are getting dirty and going the full course in the first scenes you show us, then where do we go from there?
People would be more amicable to Pia if she was teased, and scenes were spread out. But instead, she jumps your dick and we have to sit through scenes with a character we don't know or care about.
Also, the dirty talk in the scenes is way to mechanical and stiff. It's just not hot. When was the last time the dev actually had sex with a girl?
You can overcome this by putting the describing factors in internal thoughts, whilst having the characters act naturally.
So they don't need to be saying "I love having sex with you my sexy man with a nice big dick. It really increases the enjoyment of sex please have sex with my sexy body"