Council of Trent on modern "cohabitation"

[drummerboy]

 Would chapters 4 and 8 of the 24th Session of the Council of Trent, "Regarding Matrimony," be applicable to the modern trend of couples cohabitating before Marriage? Chapter 4 speaks of a first and second degree of fornication, and speaks of the affinity arising from such.  I know what affinity refers too, but what are the two degrees?  Chapter 8 regards concubinage; while modern, sophisticated, folk don't like talking about concubinage, cohabitation strikes me as practically the same, the only difference being cohabitating people often seek marriage afterwards, while in the past everyone knew what a concubine was for.  Any help would be appreciated!

[Michael Wilson]

Chapter IV explains that affinity of the first degree (immediate family, brother/sister/father/mother)or second degree in a marriage, would dissolve the marriage; but if there is fornication before marriage, it does not dissolve the marriage contracted afterwards if the affinity is beyond these first two degrees. I believe that it means that any illegitimate offspring within the first two degrees of contiguity, cannot validly contract marriage withing those degrees.   
Chapter VIII, decrees that married men carrying on an adulterous relationship, must cease this immediately, and if they do not do so after three warnings, will be excommunicated. The same for the women involved in adulterous relationships.