Txwyld - Fitness girl: after she follow you in your office, offer her whiskey right away (not: do you want to drink something). She must be smiling after you offer her whiskey! (left photo). If she doesn't, you have to start over and watch your answers coz' it's not gonna happen this time.

If she does, ask her for a strip, she refuses, you insist... It's pretty much it. I suggest you to wait for her to do the "entire" show (she tells you explicitly to restist...) because the game ends as soon as you... well, you know...
Witch - I'm sorry, I don't remember exactly what to do here, as I finished it the very first time I played and I can't re-play it because I don't have credits to spend. I remember at a certain point she asks you (or you offer) to go upstairs and make the beds... That's where the fun starts.
jimmyp - Unfortunately you are right

The "cheaper" is the fitness girl: you only need the whisky and you can re-play the game as many times as you like. That's why I ask you again: do you know a way to rip the bloody site?