This article accompanies the fable
Leonardo's frank drawings of female and male anatomy resemble his botanical drawings, for he was fascinated by the mirror patterns of the universe. But...
On the basis of this wonderful quote, many have concluded that Leonardo had no sex life. It is much more likely that his "pent-up impulse" got the better of him. The statement has rhetorical flair but little truth to it. Indeed there are sexually feminine allusions to be found in Leonardo's work that are absent in Michelangelo's. Below are two of his drawings of plants in his notebooks that strike me as feminine.
They are more subtle than the images below which are scientific and dispassionate and which derive from his dissection of corpses, a risky activity that attracted the attentions of the Inquisition when he was in Rome. The upper one is Coition of a Hemisected Man and Woman (1492); notice the nerves(?) connecting the penis to the spinal cord. Not sure the other more striking image has a title but I have read that the accompanying text and drawings discuss how the anal sphincter functions. These are all in the Windsor Castle Royal Collection.