Hi. I don't know if you still have that mattress, but I agree, memory foam is the worst for stomach sleepers. As you sleep, the mattress heats up and your midsection sinks in thus you are almost sleeping in a shallow u shape. Bad for back. Now here is what I have seen in mattress stores and at home shows. Memory foam mattresses are not one big thick foam mattress. They are layers of various densities of foam, usually 4 to 6 layers. I am assuming your wife likes the mattress, so here are some possible solutions. First take a razor knife and make a small slice that you can get your hand into so you can verify that it is layers of foam. Now get a piece of 3/4 inch plywood, smooth finish on both sides so it will be easier to slide in and out. You will want to rip (cut) the plywood to half the width of the bed so if it is a queen mattress than 1/2 of 60 or 30 inches. Now for the length, there are 2 ways you can try. Way #1, you can use a full head to toe cut. A regular queen is 80 inches so cut the board 77 or 78 inches for the length. Way #2, cut the length to go from above your knees to mid chest probably about 3 feet in length. Now the part that your wife is going to hate (Do it when she is not home ) Use your razor knife and slice open your side of the mattress. On your side only. On the side of the mattress. If you use way #1 then you'll have to slice the full length. If you do way #2, just enough to get the plywood in. Now lets say that you have 5 layers of foam. Slide the board in between layers 3 and 4. Try it for a week. If it is still too soft, move the board up a layer or too hard then move the board down a layer. Way # 3, the memory foam is usually the top 1 or 2 layers, you could try to remove just your side of those layers. This way would probably be the hardest and you would have to cut on the top of the mattress to cut down the middle. Once you find the optimum position and situation for you, either sew the openings shut or install a zipper. Have to appease the wife. Good luck, hope this helps if you still have that mattress. For future reference, I have found that a firm mattress, not extra firm, not hard, not soft and not memory foam works best for me, a fellow stomach sleeper. Also I like a latex mattress, which is foam but not memory foam. Again, good luck.