That’s a difficult one. Due to their target audience, a lot of them are more focused on storytelling (usually limited gameplay and more reading along in a choose your own adventure style) for a single player. What you’re describing is a bit of an untapped market, but give F95zone.to a look and you might find something. It’s a site dedicated to collating freely available adult games (with ways to support the authors linked). It’s where a lot of the games OP talks about found their audience.