Tell Grace that she has nice tits. Go ahead, do it.
When you, Trip, and Grace are all gathered in the living room, and there is an awkward silence, try typing in "I've got a raging hard-on right now" or something equally as shocking, then watch their faces.
Go into the game's sound files and just change the "Trip" folder's name to "Grace", and vice versa. The game becomes completely unwinnable without subtitles, but it turns both Trip and Grace into nutjobs who talk about drinks when you mention their parents or kick you out of the house while babbling about hiring a cleaning crew.