Here's a riddle I used in a game some time ago. Not the best riddle ever, but we had fun solving it.
It was written on a translucent door, on the frame of which was written "He who holds the answer may enter". What's the riddle about and what would your action be?
We're quite the couple, you and I If you let me live, I'll surely die If you kill me to live another night I'll be there next evening, at your side I won't keep you warm, I'll give you that And I am most cold when I wear my hat Whenever I cry you just leave me be while your tears are like poison to me I see the pain in your eyes, whenever we touch I shiver when you speak or shush If we're too passionate you'll surely die We're quite the couple, you and I