This is why I chose never to get married, although I managed to get my partner into gaming via Steam. How? She loves South Park, so I bought her The Stick of Truth, which can run on a potato (and also plays like an episode), and the rest is history. I guess I lucked out.If I install any game via Steam she is uninstalling it before I wake up in the morning and she has the support of my mother now.
Also, out of curiosity, why does your spouse have access to your Steam account? Isn't that your private space?