Where has this been all my life?!
Ford (yes, the same Ford that makes cars and trucks) is working on a "smart bed" that will return your partner back to their side of the bed when they roll over onto your side! It uses a conveyor belt system to gently move them back over.
I don't know how you'd put sheets on this, and I don't know how it would work without waking you both up...but it's still pretty genius!