Rule 983 There is no privilege under this article in a proceeding brought by or on behalf of either spouse to establish his competence.

If a court case is specifically about whether a husband or wife is mentally competent, the normal protections that keep private conversations between spouses secret do not apply.

This means that in a competency hearing for one spouse, the other spouse can be asked about private conversations and communications. The usual rule that lets married people keep their private talks confidential gets set aside in this specific type of case.