Is it permissible for a Muslim to read scientific books on sex that do not contain pictures, in order to learn how to approach his wife, especially if he lacks experience in this matter?

There is no objection to specialists in medicine, venereal diseases, and similar fields who need to increase their knowledge, reading books on sex. As for non-specialists, it is not permissible for them to do so, because reading such books arouses lust, corrupts thinking, and preoccupies the mind with what is not beneficial. Justifying reading them by claiming to learn how to approach women is a weak argument, for a person knows that by their very nature.