Ignorance of pious people about sexual issues is problematic Rav Yitzchok Scher

 Rav Yitzchok Issac Sher (Kedushas Yisroel #1 page 4) The pious tzadikim think that they know everything from the books such as the Shaloh and Reishis Chochma that they diligently study in these matters. They are fully convinced that according to the Torah that any type of desire is impure. Consequently their lust grows extremely strong and pushes them in path of genuine impurity. Therefore they do not talk with their wives in these matters in order not to arouse their lust. So when they come to fulfill this mitzva they wake their wife from sleep and ask or request permission to do the mitzva with her. She of course agrees because she was told by her mother that this is the way the righteous conduct themselves. So he fulfills the mitzva as one being forced against his will by a demon. And he separates himself from her immediately in order to avoid spiritual impurity. Despite his precautions he is worried that he had intercourse because of lust that was aroused in him during intercourse and that it caused him to forget all his holy thoughts that he had planned having. He is comforted when he hears from his friends that they are worried like he is. And they dismiss their concern by noting that the Torah was not given to angels and they pray for Divine assistance in this matter. He comforts himself by saying that he tried his best to fulfill G-d’s mitzva and there is nothing he could do that would make a difference. . [Note: When I asked one tzadik Why if their approach was good than why didn’t they have good children? Most of their children are unintelligent or wicked. I received the answer that this one of the mysteries of creation because even the great tzadik King Chezkiyahu had the evil Menashe as a son.. Consequently after I became aware of these difficulties which most men have and after I carefully studied the Letters of the Ramban on these matters, I realized that they erred in properly understanding the matter. Possibly because they had quickly and superficially studied it. In fact the words of the Ramban are precise without any superfluous language and they need to be studied deeply and carefully in order to appreciate what he means. Anyone studying them properly will see amazing insights that accord with the Torah.  In the second chapter which deals with the nature of intercourse and that it is in fact  holy and pure. Next in chapter 3 which talks about the timing  it is entirely an innovation that the mitzva is to properly prepare physically the body and temperament that it shouldn’t be hot or cold and that the semen should not be foul and he is able to be patient with intercourse. In that case the wife will ovulate first. It is also well known that whoever is born from a hot drop of semen will be an angry and temperamental person. In contrast, if he is born from a drop of moderate temperature, he will be wise and calm and even tempered and get along with everyone. The 4th chapter describes the appropriate food to eat which also influences the holiness of intercourse and whether the child is wise or foolish,  righteous or evil.  The 5^th chapter describes the appropriate thoughts during intercourse. Finally in the 6^th chapter he clarifies the obligation of speaking to his wife with love and romance, fear of G-d and modesty.