What does "5-year cohabitation" mean?

Jurisprudence has laid down the rule that the five-year common-law cohabitation period under Article 76 means a five-year period computed back from the date of celebration of marriage, and refers to a period of legal union had it not been for the absence of a marriage. (Niñal v. Bayadog). It covers the years immediately preceding the day of the marriage, characterized by exclusivity – meaning no third party was involved at any time within the five years – and continuity (that is, unbroken).