To me, first dates are too soon to ask. But it definitely makes sense to know a potential partner's score before the relationship goes too far — at least, for people with marriage on their minds. A partner who can't get credit at a decent rate could pull down your mutual standard of living.
Your FICO Score is the best known, most used and most relevant to disclose. The three major credit bureaus (Equifax, Experian and TransUnion) also provide a VantageScore, based on a different scale. FICO scores come free if you apply for credit, and the score influences the decision. Otherwise, you’ll pay $19.95 for an Equifax or TransUnion score. (Experian won’t give you FICO scores. You get a VantageScore for $7.95, which isn’t comparable.)