(c) The pleasure intended or consented to is venereal; that is, such as is consummated in copulation or pollution. Hence, there is no sin of lewdness when the acts in question are performed becomingly and with and for pleasure of a spiritual kind (as when members of a family give one another the customary kiss or embrace of affection), or of a merely sensual kind (e.g., when a nurse kisses the tender skin of an infant). On the distinction of intellectual, sensual and venereal pleasures see above (2461).
(d) The external act is not consummated by copulation or pollution. These are often its result but they are a different degree of sin, and lewdness is committed even without them (see 2486).
(e) Lewdness is an action not directed to the conjugal act. Coition itself is lawful in the married state, and this legitimatizes all the preparatory or accessory endearments. Hence, the rule as to married persons is that venereal kisses and other such acts are lawful when given with a view to the exercise of the lawful marriage act and kept within the bounds of decency and moderation; that they are sinful, gravely or lightly according to the case, when unbecoming or immoderate; that they are venially sinful, on account of the inordinate use of a thing lawful in itself (85 a), when only pleasure is intended; that they are mortally sinful, when they tend to pollution, whether solitary or not solitary, for then they are acts of lewdness. The rights and duties during courtship and engagement will be treated below in Question III.
2511. Cases Wherein No Sin Is Committed.—Since lewdness proceeds from or is accompanied by culpable venereal pleasure, it does not exist in the following cases:
(a) in children who have not attained puberty and the capacity for sex pleasure, and hence there is no sin by reason of proximate danger in looks or touches exercised by them, which would be gravely sinful in those who have reached the age of puberty. These children may, however, sin against modesty or obedience, at least venially. They should be trained from their earliest years to reserve and decency, and it is a most serious sin to scandalize their innocence. The question of sex instruction for the young will be dealt with in the Question on the Duties of Particular States. If an adult person were as unmoved as a child by the stimulus of passion, such a one would incur no personal guilt of lewdness by kissing and the like acts, but such an adult person is very rare;
(b) in adult persons when a dangerous act is exercised by them, without consent or proximate danger, and with a sufficient reason for the exercise. Thus, a student of literature may read an erotic story from the classics, if he is proof against the danger and intends only improvement in style, though for the young such books should be expurgated; a professor of medicine or moral theology may discourse prudently to his students on venereal diseases or sins; an artist may use naked models in painting, if and as far as this is necessary; farm hands may attend to the service of female by male animals; looks and touches that would otherwise be immodest are lawful for proportionate reasons of utility, as in bathing oneself, in performing the services of nurse or physician for others, etc. (see 2497 sqq.).
2512. Conditions Governing Propriety of External Acts.—The becomingness of the external acts spoken of in 2510 b includes two conditions.
(a) On the side of its object, the act must not be directed unnecessarily to the parts of the body that are shameful and private (i.e., the genitals and immediately adjacent parts). It is customary to distinguish the remaining or non-shameful parts of the body into becoming, which are uncovered (e.g., face, hands, feet), and less becoming, which are covered (e.g., legs, breast, back). But as to less decent parts much depends on local usage. For example, at a bathing beach it is not unbecoming to appear in a mixed crowd with uncovered legs or arms, and in very warm countries it is not improper to go about in public with less clothing than is worn in colder climates.
(b) On the side of its subject, the act must be performed with moderation and respect for reasonable custom. Thus, columbine (popularly called “French”) kissing and the ardent or prolonged embraces known as “necking” or “petting” are admittedly indecent, even when not accompanied by sexual excitement. Oral abuse committed by or with either sex is indecent both as to the object, i.e., the part of the body involved, and as to the subject, i.e., the mode of action. It is the filthiest form of lewdness and is usually joined with pollution (irrumation).
2513. Morality of Kissing and Similar Acts.—(a) _Per se_, or from their nature, these acts are indifferent, since they can be employed, not only for evil (Job, xxxi. 27; Luke, xxii. 48), but also for good, as we see from the examples of the kiss of peace (I Thess., v. 26), the kiss of fraternal greeting (Gen., xxvii. 26, 27), and the kiss of respectful homage (Luke, vii. 38, 45).