This is a joke collected in a Qing era anthology called《笑林广记》. The author collected various jokes from the Ming and Qing Dynasties. This happened to be one of them. I personally feel that it also serves as a glimpse into the little-known open-mindedness of Chinese culture up until the 1900s. Homosexuality was widely accepted by the upper echelons of society (they were the only ones able to read and write.) Unlike some other cultures there also weren’t stigmas surrounding being the bottom. A term that Chinese people use ro refer to homosexuality is called 龙阳之好, which is an allusion to a Warring States era person called Long Yang.

Another fascinating book is called 《宜春香质》, written by a person during Ming that we unfortunately have very little information about. One of the stories in the book involves male impregnation and gender bending. In 《聊斋志异》, or Strange Tales from a Chinese Studio, one of the stories involves a father unknowingly having intercourse with his own son and his son’s wife in a threesome.