Sexual education was never considered to be one of the merits of a virtuous wife in European tradition whereas it was quite the opposite in China: a good wife or a concubine had to be able to please her husband by means most refined and dainty, what is more not only had she to let other women have her husband but also had to attend upon them during the intercourse. And although rigorous Ñonfucians might have been displeased no one was condemned for these transgressions.
It's curious to know that despite such a sexual liberty Chinese didn't recognize public kissing and took it critically - no matter whether severe Confucians or sexually free Taoists were to judge. Taoists were failing to understand why one would dissipate one's energy on caressing that won't lead to a natural culmination. They considered it to be insulting to the origins of yin and yang. Charles Human and Wang Wu wrote in their work "The Chinese Way of Love": "When Europeans started settling in Shanghai and other cities one could often see how husbands and wives greeted each other with a kiss or a hug; when observing scenes of the kind Chinese would expect that a European would loose his "spear" and rush to the attack. Even more were Chinese confused when two Frenchmen greeted each other with kisses on both cheeks - that too seemed to them a wasteful sexual round about." As of Confucians who believed that men and women should walk on different side of the street, public kissing, even between husband and wife, seemed to them an utmost dissoluteness.
Oleg Ivik "History of sexual proscriptions and prescriptions"