Please look at the game Veto (http://www.fatamorgana.ch/fatamorgana/veto/index.html in German, sorry). It's a nice little innocent game where you have a kid and have to make decisions about upbringing. Essentially, your kid tries to do something, and you can decide to veto or not.
Now imagine a re-theme: You play a woman on a date. The man tries certain actions, and you veto or not. Adding a few pictures may enhance the appeal. (Or the game does not simulate a date, but perhaps a relationship.)
In the original veto game, there's no explicit goal, but different endings. If you want, you can create your own goals (like make your child as succesful as possible). In the dating game, you could try to get a lot of gifts before you sleep with the guy (or marry him, depending on the scope of the game). Or you could try to get him to do kinky (or normal ;o) things. Etc.
In most adult games, getting the girl is the goal. But it would be funny to make that part of the tools.
What do you think?