Dude, if your girl is bi and like this kind of thing, there are several yuri novels out there but almost none of them are animated. If she is not bi and dislike yuri, things start to get difficult because there are no games with "Fifty Shades" plot or written specifically for the average girl in this market (as far as I know). Nevertheless I'm gonna recommend you some games that she may like based in the animation's quality or plot:
-Illusion games have very good animations but they don't have a "deep" plot or a story at all.
-Harem Hotel is a great game, good animations and plot, tho I don't think that a woman would like it, you know the idea of having an Harem is not that appealing for a girl.
https://f95zone.to/threads/harem-hotel-v0-8-2-runey.12760/
-SyFy themed, it has a simple action/adventure plot and one of the most realistc and fluid animations in an adult game
https://f95zone.to/threads/rogue-courier-v3-09-00-silver-pinoytoons.1333/
-Not animated but has a great plot and is written by a woman (If I'm not mistaken). It has so many paths and give you so many options that I bet your gf would like it.
https://f95zone.to/threads/good-girl-gone-bad-v0-31-evakiss.2633/
