Well, if it were me… I’d already know the answer, wouldn’t I? 
The trouble with a lot of porn games is they are neither good porn nor good games. There have been other threads on the subject, but the short (ahem) of it is, they tend to be boring, inane, and not especialy tittilating. If you’re getting a gag gift, that’s one thing. If you actually want to give your friend something he will like after the humor wears off, you might want to make it a combo gift: part gag, part sincerity.
Yeah, I played it on the C64 too, but being a text adventure, I’m sure it was put out on about every platform including DOS (I’m not sure if Windows was around then). I never got all that far in the game, just assumed it was risque from the way it was marketed. Figured there had to be some R-rated stuff in there at the very least.
The guy did say he was looking for not even out and out porn.
The old ones won’t work on XP, and the new one supposedly does not have as much of the humor. I’ve heard it’s more oriented towards games instead of puzzle solving.