Maybe he did not know how to proceed with the story or lost interest.
I wrote a few stories myself and when the story got to the interesting part and the first extramarital intercourse happened my enthusiasm was gone and I completed the story lukewarm or aborted it.
The game ended with the wife cheating, it was the climax of the game so far and maybe the developer lost interest afterwards.
I think this is one of the common denominators for anticipating when a game will fail. Time and again we see games collapse just as things are about to get good. Heck, I did some editing/proofreading for a game that suffered the same fate. Just as the action was about to pick up the dev went radio silent. While I've spoken to them and they insist they will complete the game, and I trust that they don't have nefarious intentions, the timing can't be denied. So there's something about "slow burn" games that make them prone to collapse at the inflection point. When the game transitions from establishing the tension to paying off that tension, devs seem to drop like flies.
So I think there's a weakness in the genre itself. Games like this craft stories that become inflexible, and too focused on the inflection point where the MC
finally has sex, at the expense of the completed story. We spend months, if not years, building up to something that should be the launching off point. This launching point/inflection point should be when we get the most fun, but instead it almost seems to be letdown. You can almost feel the whole thing becoming a burden, as trivial baby steps have to be completed because the story has become too inflexible. We never get to enjoy the wife's infidelity because it's taken too long to get to that point.
Adult games are awash in mindless fuck fests, and I applaud games like WMW that try to be more. But these slow burns seem to forget one really important detail, these games are supposed to be fun. Their stories become too self serious, too humorless. I think we forget that most players spend the majority of their time with their hands down their pants; we need devs to loosen up a little. A good slow burn can still have sex early and often, we don't need to wait years to get to that point.