I believe that “prudishness” can have quite different meanings and refer to different phenomena:
1. It may consist in a kind of exaggerated or overly great sense of shame and pudor, such as the “insuperable or insurmountable feelings of shame” of a virgin or nun not to undress for a gynecological exam or surgery even at grave risk of her health or life which “horror ingens” some traditional moralists regarded as valid reason for refusing life-saving operations or necessary medical exams. This does not have to imply per se any negative attitude towards sex but is an exaggerated and in this sense “prudish” sense of its intimacy or sacredness and disproportionate fear of the danger of desecration through revealing one’s body to others; another example might be being shocked by or blushing on even the most reverend speaking of sexual matters.
2. It may mean a hypocritical “social” negative attitude towards sex which eliminates or represses, or feels outraged by, or reacts hysterically and negatively, to any even noble speech on sexual matters while (like Queen Elizabeth) one’s private hidden life is full of impurity.
3. It may mean a non-hypocritical and sincerely negative approach to sexuality even in the context of married love because the prudish persons rejects all sexual acts because she feels sexuality as such to be something bad or dirty and something to be shunned or reduced in all its forms.
4. It may mean a kind of “mental cramp” and psychic inability to allow even one’s husband or wife intimate expressions of tenderness or to reveal one’s nakedness to him or her even in married life except to a minimal degree. This can have many roots including a fear of the power of sex and a wish to remain always in cool control, a fear to give oneself fully to any human person, a false sense of piety or purity, an unfounded fear of being touched impurely, a psychic disorder, a confusion of purity with frigidity, a lack of spousal love, disgust of overweight of one’s partner, etc.
There are also many phenomena misnamed prudishness:
4. The caution, appearing ridiculous to Waldstein and perhaps to most of us, taken by a person tempted through masturbation or other impurity, not even to look at his own body or to throw ashes in his bath tub, or to shun looking at Titian’s Venus, Michelangelo’s Adam, etc. This may be prudishness but if it is an action or caution taken for a legitimate fear of offending God through impurity to which one truly is tempted by such sights, it is not prudish at all.
5. The reluctance or refusal to allow truly impure looks, touches, or lustful abuses of one’s body even in marriage. (Rejecting what Wojtyla calls the partner’s “adultery with one’s marriage partner” belongs here). This is purity that has nothing to do with prudishness.
6. Feeling offended by what Alice von Hildebrand calls Chr. West’s vulgar or irreverent language or by his claims that oral sex or anal sex are OK in the foreplay, or that we must be grateful for Hugh Hefner’s, the hero of impurity’s, fight against prudishness (all of which points I for one think deeply false in West’s remarks and on which I do not agree with Waldstein’s, Healy’s or other whole sale defenses of West, but rather with Alice von Hildebrand, even though I think West is basically very good and Schindler’s critique goes completely overboard). Any feeling offended by the many impure, shameless and irreverent ways people demonstrate sex publicly, speak of sex, portray it in movies or pictures, etc. has nothing to do with prudishness, but with purity and a sense of appropriate acts and proper language, wherefore I think that West’s suggesting that a person questioning him on some of these points must have problems of sex is deeply wrong and grounds for his apologizing to the questioner. In spite of some justified criticisms all of us ought to thank West for his many tremendously strong and good points and forgive him is faults such as his “love for Hugh Hefner” or uttering his name in the same breath with Pope John Paul II (of course his true charity for H. and his insisting that his pronorgraphic sexual revolution very wrong, are very good).
There are still many other possible distinctions but I wrote too much already.