Hi nancy361,
Asyou probably know from much of the information on this site … the two main functions of a mattress are comfort / pressure relief and support / alignment. Part of the art and science of mattress construction is balancing these two needs because they can often contradict each other.
Pressure relief needs “enough” softness to allow the pressure points to sink in enough to relieve pressure. This is controlled by the thickness and softness of the comfort layers.
Support needs “enough” firmness to “stop” the heavier parts of the body from sinking in too far. This is controlled by the support core of the mattress (in your case the innerspring) and also by the thickness and softness of the comfort layers. If the comfort layers are too soft and thick … then no matter how firm the support core is your heavier parts will keep on going through the upper layers until they “reach” the support core while the lighter parts may be “stopped” by the comfort layers themselves before they “reach” the support core… this means that you are sinking in to the mattress unevenly and can result in the spine being flexed and held in a position which is not neutral and can be uncomfortable or even painful.
Sometimes this can be an issue with a couple who are different in their body types or sleeping positions or have weight more concentrated in different areas because they can have very different needs and preferences in a mattress and in some cases a mattress that is suitable for one may not be suitable for another. Some of the solutions in this case are discussed in the first part of post #2 here.
Another issue that can sometimes crop up is that people may choose to add more softness for the sake of “feel” more than actual pressure relief or support and this too can result in thicker and softer comfort layers and toppers that may affect one half of the partnership more than the other.
One potential solution is to change out some of the layering of the bed that can help in these types of situations (and most manufacturers will have a good idea of the types of changes that may help) and another solution as you can read in the post I linked as well is to use a a split layering either in the comfort layers of the mattress or in a topper. An example would be a topper that had a zipper and that had different materials or softness levels in each half of the topper.
While I don’t know the specifics of either your mattress or your topper … I suspect that not only is he heavier but that his weight is distributed differently from yours and he may need thicker comfort layers for pressure relief and he will sink into these more evenly while you may be lighter and sinking in to the thicker comfort layers (in the mattress and the topper combined) more unevenly because only your pelvis has enough weight to “go through” them.
In general … I normally suggest “just enough” thickness and softness to relieve pressure because this is less risky for alignment. Sometimes people who go for a much softer “feel” of a mattress that don’t really need this for pressure relief won’t really sleep any better and can increase the risk of alignment issues for either them or their partner.
Phoenix