If like Baby Bear you wonder whether Goldilocks has been sleeping in your bed, perhaps this thermosensitive pillow will give away the game.
The pillow reacts to heat, changing from gray through blue and purple to red as it heats up. The color change lasts for about a minute, so it lets you can see if someone just jumped up out of your bed or favorite chair just before you arrived.
I would be particularly concerned if you come home to your spouse, and find more than one set of hand prints showing.
At $150 it's kind of expensive, but at least you won't have to check the porridge.