Due to a minor but aggravating spinal deficit, I must sleep on my back on a rigid surface. My bed consists of the normal box springs and mattress, but with a foam-padded sheet of plywood on top of the mattress. Since my wife must sleep on a soft mattress there exists a bit of disparity. This was resolved by the purchase of two twin beds. I made adjustments so that the upper surfaces are at the same plane. However, the bed(s) are made up as one. The sheets and blankets are king size, and a form fitted bottom sheet fits over both mattresses. From outward appearances it is a normal king size bed.
This produced a collateral benefit when I acquired RLS since my movements are less intrusive to my wife's sleep than if we had a single mattress. For those whose leg movements are more intense, the solution might be to have twin beds made up with separate sheets and blankets, with a slight separation between the beds. There would be sufficient proximity for conjugal visits.
A king-size bedspread would solve the ethetic appearance of the set up.
Maybe not the perfect solution but, hey, it ain't a perfect world.
My husband was cracking up the other day because ours got up to cuddle on the couch with me and then pushed with his feet until I was practically in my husband's LAP! (No one complained, of course! ) 