Although "share and share alike" is the general philosophy of community property law, inheritances are treated differently. They belong to the beneficiary, separately. So, unless your mother-in-law specified in her will or trust that she was leaving the house to both of you, the house belongs to your husband alone. But tell him it's not polite to sit in it by himself and gloat.

Learn more about community property in Marriage & Property Ownership: Who Owns What?