We are defendant''s in a credit card case. If a judge/plaintiff makes a request for admission, can husband-wife and/or 5th Amend.privledge be invoked

A person may invoke his or her 5th Amendment right against self-incrimination at any time, even in a civil case.  However, if the person is under an affirmative obligation to respond to discovery, such as Requests for Admissions, the invocation of the 5th Amendment and refusal to respond to the Requests for Admissions can, in certain situations, be used against you in the civil case.  In other words, if you refuse to respond to the Requests for Admissions, the Court may enter Judgment against you (even if the reason for the refusal to answer is based on the 5th Amendment).  Regarding the husband/wife privilege, I am unaware of any case law which would allow a husband and wife to refuse to respond to Requests for Admissions in a civil case based on the marital (husband/wife) privilege (assuming both the husband and wife are defendants in the case).