Two things. What some people do is mostly irrelevant as we are examining the larger picture here of what is moral and what is not moral. What you’ve described above would definitely be sinful. Trouble is, I’ve heard some Catholic resources say that touching the genitals of the other person (not their own) would be considered masturbation of that person even during coitus. Clearly there is confusion.
As for Kinsey’s findings, while I’ve not read them, it would seem rather awkward for a couple to engage in foreplay for that period of time while avoiding all genital contact.
This is why there needs to be clarification of what exactly masturbation is. The CCC states it in a way that basically describes the process of the sex act itself. The sex act IS deliberate stimulation of the sex organs, and it is the derived pleasure that leads to climax of the act. If a man’s sex organs were completely numbed, he would be unable to engage in sexual intercourse as there would no sensation, thus no pleasure.
What is it that makes masturbation an evil? It misuse of the sexual faculties purely for pleasure. This is why those who engage in sexual intercourse while using birth control is sometimes called “mutual masturbation.” This can also be applied to the sin of “Onanism.” The thing about Onanism is that the sexual intercourse ONLY becomes mutual masturbation when the man withdraws before climax. The ends do not justify the means if the means are evil, but the means are not disconnected from the ends either.
There is a difference between pleasure and sensation. Some people that are hypersensitive find sexual sensation unpleasurable.
After all these posts, I think two terms are less confusing with reference to sin: autoeroticism and unchaste conjugal acts. What do you think?
What is certain is that autoeroticism is sinful, and the term is used by the Magisterium (see below). There can be confusion about masturbation depending upon the definition used. Withdrawal needs its own defintion but defeats the end (finality) of the sexual faculty like autoeroticism, in each instance. What I have seen in the Catholic documents does differentiate autoeroticism from conjugal acts (see two sections below), and the main answer to the question “What is it that makes masturbation an evil?” is given below from Persona Humana:
A. Autoerotocism:
- “acts of autoeroticism are objectively intrinsically evil” (CDF: Notification Regarding Certain Writings Of Fr. Marciano Vidal, C.Ss.R., 2)
- “masturbation is an intrinsically and seriously disordered act” (Persona Humana 9)
- “the deliberate use of the sexual faculty outside normal conjugal relations essentially contradicts the finality of the faculty” (Persona Humana 9)
You wrote: “I’ve heard some Catholic resources say that touching the genitals of the other person (not their own) would be considered masturbation of that person even during coitus.”
Conjugal touch can be sinful if both are using each other such that the focus is on the sensation rather than on the loving exchange.
Allocution to midwives makes it clear that it is possible to sin in the way the act is performed.
B. Chaste conjugal acts:
- “The acts in marriage by which the intimate and chaste union of the spouses takes place are noble and honorable” CCC 2362
- “And this law, so very reasonable, concerns not only the substance but also the circumstances of the action, so that, even when the substance of the act remains morally safe, it is possible to sin in the way it is performed.” (Pope Pius XII: Allocution to midwives, October 29, 1951.)
You wrote: “The thing about Onanism is that the sexual intercourse ONLY becomes mutual masturbation when the man withdraws before climax.”
To determine a sin, we look at each act in one instance. So the withdrawal is the sin. But “mutual masturbation” is both using each other for sensation rather than a loving exchange open to life. (I saw this term used for married couples using artificial birth control, but it could also apply to married couples using NFP without a grave reason.) It is beneficial to reflect of the difference between these two different behaviors. (I get vs I give.)
Sometimes marital acts are venial sins, which can lead to mortal sins. If unnatural acts are done that is grave matter. The ends do not justify the use of intrincly evil means. (Skipping a list of examples.)