I kind of see where you are coming from but the game is called Nympho Tamer and she's a nympho. Like I get not having sex day 1, you're setting up the story, but what from you've written/set-up it actually makes no logical sense why it hasn't happened yet. There isn't anything slow about her corruption, she's already corrupted which I think is the reason people have a problem with her not having a single sex scene yet. It would be understandable if she didn't already trust him with her mind and body at this point. She'd do just about anything he'd ask already only thing stopping her is literally just him not asking.
If her having sex would "finish" the story then that's a problem cause it just means the scenes will be delayed for no logical reason. Contrary to popular belief you can progress quickly with the "main" girl and still create a compelling game. Personally, I thought the story would be about the MC swooping in, swiftly dominating her life and then have her explore wilder fetishes and helping him corrupt other characters. For a more slow-burn approach to her corruption to make any sense at this point from what we've seen of the story/characters, you'd have to start over.
You have the start of what could be a very good game but the characters themselves aren't making much sense at the moment. Its a porn game at the end of the day so I'm not expecting something super in depth or anything, just characters that are consistent whose actions make sense with what we are told about them. Don't get me started on the ex-girlfriend. She's supposed to be some independent career driven woman. Yet when things went south she went to a strip club and had a stranger make her get plastic surgery instead of simply asking her ex for help. Her pride isn't an excuse here, since what she chose to do was way more demeaning than asking for help.
Tldr, game has potential, started off good but is starting to drag for a game based around nymphos and the characters themselves don't make much sense when you step back and look at things logically when considering the narrative we are given so far.