The Hitchhiker

You probably should have known better than to stop on the side of the road for someone. The person just looked hurt and was cold in the rain... You couldn't just leave them there. You help them into the passenger's seat of your car, and you offer to take them to the nearest hospital. To your horror, they pull a knife and demand that you instead take them home with you... and you live alone. (Not necessarily a romance prompt, but this one has been kicking around in my head for a while based on a game I saw. I feel like the ambiguity of the stranger's intentions in this scenario makes it more thrilling.)