2614. The Obligation of Paying the Conjugal Debt.—(a) The duty is one of justice, since it arises from the contract of marriage, in which the parties freely and solemnly bind themselves to it as the subject-matter of their pact.
(b) The obligation is grave, since the marriage contract is one of the most momentous of human agreements, its direct end being the propagation of the race, while the denial of its essential right is productive of most serious evils, such as incontinence, scandals and the disruption of families. There is light matter, however, as when the request is not imperative, or the denial is infrequent and without danger of incontinence.
2615. Absence of Obligation.—The obligation of paying the conjugal debt does not exist, however, when the right to make the request has been lost or when the request is unreasonable.
(a) Thus, the right to make the request is lost when one party has broken faith by committing adultery and has not been forgiven by the innocent party, and also when one party is incapable (e.g., on account of insanity or drunkenness) of asking in a rational manner.
(b) The request is unreasonable, first, when it is immoderate (e.g., when it cannot be granted without serious and unusual detriment to health, or without danger of death, or without likelihood of abortion or other great harm to a child conceived or to be conceived); secondly, when it is seductive (e.g., when it is an invitation to commit onanism).
2616. Suspension of Obligation.—The obligation of granting and the right of requesting conjugal relations are suspended when the marriage is discovered to be null or uncertain.
(a) Thus, if the marriage is certainly null, abstinence is necessary until the marriage is made valid; otherwise the parties are guilty of fornication. But if nullity is due to a merely ecclesiastical impediment, the impediment probably ceases in cases of most grave inconvenience when the nullity is known to only one spouse and the dispensation cannot be obtained at once.
(b) If the marriage is only doubtfully null, abstinence is not necessary unless both parties have a serious doubt and no examination has yet been made. Light doubts should not be considered, nor doubts that have not been corroborated by investigation; while, if only one party doubts, he or she cannot refuse the debt lest injustice be done the other.
2617. Is There an Obligation of Requesting Conjugal Intercourse?—(a) _Per se_, there is no obligation, since one may lawfully decide not to enjoy one’s right, and not to use what belongs to one. As man and wife were free to marry or not to marry, so are they free to agree either to consummate or not consummate marriage. It is even lawful for married people to contract together to abstain temporarily or permanently from marriage relations (e.g., for the sake of health, or of economy, or of mortification). By mutual consent one or both may make a vow of chastity, as was done by St. Joseph and the Blessed Virgin, or the husband may enter the priesthood and the wife become a nun.
(b) _Per accidens_, there is often an obligation of requesting intercourse, for experience shows that continual non-use of marriage often leads to incontinence or to loss of affection (see 2228).