The most common form of ownership of a property between couples or spouses is a joint tenancy.
One of the ramifications of a joint tenancy is that the principle of the right of survivorship applies.
The right of survivorship provides that if one of the joint tenants dies their interest will not pass onto their estate (regardless of what is in their Will).
An example of same is A and B purchase a property as together as joint tenants. B dies first and therefore the property automatically goes to A.
If there are several owners of the property the same principle applies and the last person surviving will inherit the full share.
Once the last person inherits the property they are free to do as they wish.