Which of these describes your relationship to a Portuguese citizen?
Portugal — Marriage
Portuguese nationality by marriage is a declaration rather than an application, and it does not require you to have lived in Portugal at all. Because the rule is written around marriage and around judicially recognised unions specifically, the exact status of the relationship decides whether the route is open — so pick the answer that is literally true rather than the closest one.
I'm married to a Portuguese citizen → We live together and aren't married — a união de facto or an equivalent partnership → I'm separated or divorced from a Portuguese citizen → My Portuguese spouse has died → My partner is a citizen of another EU country, not Portugal → I'm not sure whether my spouse actually holds Portuguese citizenship →