In reading the excerpts of the case, one thing stands out:
Justice David H. Souter, for the majority:
"There is no common understanding that one co-tenant generally has a right or authority to prevail over the express wishes of another, whether the issue is the color of the curtains or invitations to outsiders.
"Since the co-tenant wishing to open the door to a third party has no recognized authority in law or social practice to prevail over a present and objecting co-tenant, his disputed invitation, without more, gives a police officer no better claim to reasonableness in entering than the officer would have in the absence of any consent at all."
This could only be the words of a justice who has never been married, and who therefore should recuse himself from any case that requires knowledge of the marraige relationship.
No man who has ever been married would doubt who prevails in an argument over the color of the curtains, OR in whom may visit the house and when.
And yes, Souter has never been married.