A few months ago, Barton Waterduck discovered a few sections of unused code in the PS2 version of San An for the girlfriend "missions". With a bit of memory hacking and such, he discovered these removed portions of mission scripting were to not only put the camera inside the girlfriends' house when you stop in for "coffee", but also to make a little mini-game of it. Now, with the magic of user-editable files on the PC, PatrickW was able to unlock the uncensored "coffee" segments for all to play with. Here's a few screens, but be warned, they might be a bit on the NSFW side...
If you want to try it out, head on over to GTAGarage to download this mod.