I understand that, I was just responding to the idea that, even though it might be “most”, a significant percentage of couples do not cohabitate, nevertheless, that does not mean they are remaining chaste. If there were absolutely no danger of unchastity, as might be the case with elderly couples with low libido, it would be very difficult to make a case against living together, even without benefit of engagement.I wasn’t (and am not) speaking of chastity in general, just cohabitation.
I know of one elderly couple who are very explicit that they live together for financial reasons (to be able to keep their pensions and benefits that they would lose if they legally married), and that there is “nothing going on”. I take that at face value, and to those who would echo the modern refrain that “it’s none of anybody else’s business”, I would only say that there is such a thing as giving scandal, and they are absolutely right to make their circumstances known, precisely to keep from giving scandal. The lady partner in the couple is a faithful Catholic, participates fully in parish sacramental life, the pastor has no problem with it, and neither do I.