When a spouse has been unfaithful

Am I allowed to leave?

These paragraphs are not in the Catechism’s own order. The one that answers the question directly is placed first; none has been left out.
1649

Yet there are some situations in which living together becomes practically impossible for a variety of reasons. In such cases the Church permits the physical separation of the couple and their living apart. the spouses do not cease to be husband and wife before God and so are not free to contract a new union. In this difficult situation, the best solution would be, if possible, reconciliation. the Christian community is called to help these persons live out their situation in a Christian manner and in fidelity to their marriage bond which remains indissoluble. Cf. FC 83; CIC, cann. 1151-1155.

1646

By its very nature conjugal love requires the inviolable fidelity of the spouses. This is the consequence of the gift of themselves which they make to each other. Love seeks to be definitive; it cannot be an arrangement "until further notice." the "intimate union of marriage, as a mutual giving of two persons, and the good of the children, demand total fidelity from the spouses and require an unbreakable union between them." GS 48 # 1.

1647

The deepest reason is found in the fidelity of God to his covenant, in that of Christ to his Church. Through the sacrament of Matrimony the spouses are enabled to represent this fidelity and witness to it. Through the sacrament, the indissolubility of marriage receives a new and deeper meaning.

1648

It can seem difficult, even impossible, to bind oneself for life to another human being. This makes it all the more important to proclaim the Good News that God loves us with a definitive and irrevocable love, that married couples share in this love, that it supports and sustains them, and that by their own faithfulness they can be witnesses to God's faithful love. Spouses who with God's grace give this witness, often in very difficult conditions, deserve the gratitude and support of the ecclesial community. Cf. FC 20.

2383

The separation of spouses while maintaining the marriage bond can be legitimate in certain cases provided for by canon law. Cf. CIC, cann. 1151-1155. If civil divorce remains the only possible way of ensuring certain legal rights, the care of the children, or the protection of inheritance, it can be tolerated and does not constitute a moral offense.

2386

It can happen that one of the spouses is the innocent victim of a divorce decreed by civil law; this spouse therefore has not contravened the moral law. There is a considerable difference between a spouse who has sincerely tried to be faithful to the sacrament of marriage and is unjustly abandoned, and one who through his own grave fault destroys a canonically valid marriage. Cf. FC 84.

1152

§1. Although it is earnestly recommended that a spouse, moved by Christian charity and concerned for the good of the family, not refuse forgiveness to an adulterous partner and not disrupt conjugal life, nevertheless, if the spouse did not condone the fault of the other expressly or tacitly, the spouse has the right to sever conjugal living unless the spouse consented to the adultery, gave cause for it, or also committed adultery.

§2. Tacit condonation exists if the innocent spouse has had marital relations voluntarily with the other spouse after having become certain of the adultery. It is presumed, moreover, if the spouse observed conjugal living for six months and did not make recourse to the ecclesiastical or civil authority.

§3. If the innocent spouse has severed conjugal living voluntarily, the spouse is to introduce a cause for separation within six months to the competent ecclesiastical authority which, after having investigated all the circumstances, is to consider carefully whether the innocent spouse can be moved to forgive the fault and not to prolong the separation permanently.

1153

§1. If either of the spouses causes grave mental or physical danger to the other spouse or to the offspring or otherwise renders common life too difficult, that spouse gives the other a legitimate cause for leaving, either by decree of the local ordinary or even on his or her own authority if there is danger in delay.

§2. In all cases, when the cause for the separation ceases, conjugal living must be restored unless ecclesiastical authority has established otherwise.

1154

After the separation of the spouses has taken place, the adequate support and education of the children must always be suitably provided.

1155

The innocent spouse laudably can readmit the other spouse to conjugal life; in this case the innocent spouse renounces the right to separate.