5. Adultery or fornication, committed after a contract, being detected before marriage, giveth just occasion to the innocent party to dissolve that contract. In the case of adultery after marriage, it is lawful for the innocent party to sue out a divorce, and after the divorce to marry another, as if the offending party were dead.As we see, the conditions laid out by Article 5 allow divorce in the instance of adultery, if the innocent party desires. If the divorce is granted, it is "as if the offending party were dead." In Article 6, a second condition for divorce is given, being "willful desertion." Were one's spouse to abandon them, the marriage could also be dissolved.
6. Although the corruption of man be such as is apt to study arguments, unduly to put asunder those whom God hath joined together in marriage; yet nothing but adultery, or such willful desertion as can no way be remedied by the Church or civil magistrate, is cause sufficient of dissolving the bond of marriage; wherein a public and orderly course of proceeding is to be observed; and the persons concerned in it, not left to their own wills and discretion in their own case.
But from the beginning of creation, 'God made them male and female.' Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh. What therefore God has joined together, let not man separate. - Mark 10:6-9