Let's Talk About Sex
Today, the sex lives of celebrities are fair game for tabloids, TV talk shows, and dinner table discussions. In the Renaissance, gossip was probably a similar occupation, although without the modern media frenzy the pace of the rumor mill was probably a bit slower! Even so, Leonardo was notoriously secretive about his personal life. It's possible to read between the lines, however, and try to figure out what was going on in Leonardo's personal life.
Was He or Wasn't He?
Many aspects of Leonardo's life indicate that he was most likely homosexual, although there is no direct evidence of this allegation. In addition to his likely long-term relationships with Salai and Melzi, there are also indications of Leonardo's sexual orientation throughout his work and life.
Leonardo never married, and he is never recorded as having shown any nonprofessional interest in women whatsoever. He even expressed his disgust for male-female sexual intercourse in his notebooks. A famous quote from his notebooks reads:
“The art of procreation and the members employed therein are so repulsive, that if it were not for the beauty of the faces and the adornments of the actors and the pent-up impulse, nature would lose the human species.”
The Evidence
Some evidence of Leonardo's views of the female sex can be found in his drawings and paintings. Leonardo's anatomical sketches include drawings of both male and female genitalia. While the drawings of male sexual organs are detailed and accurate, the female genitals are depicted with less detail and accuracy; more often Leonardo used them for his medical studies. Perhaps Leonardo had more ready access to male models than to female ones, but this disparity could also indicate Leonardo's disinterest in the female body.

Some of Leonardo's drawings may also suggest, in a more symbolic manner, his distaste for heterosexual intercourse. Many of his sketches and paintings depict phallic rock formations and womblike tunnels and caverns, rendered so as to appear harsh and unappealing. Is this analysis the product of modern interpretation, or was it Leonardo's original intention?
Androgynous Art
In spite of Leonardo's seeming preference for the male figure, he did not always portray these figures as hyper-masculine. For example, in Leonardo's famous work The Last Supper, St. John is very effeminate-looking and appears even somewhat androgynous. This portrayal has actually led to talk that the figure at Christ's right is actually a woman, with some art historians speculating that the figure may have represented, not St. John, but Mary Magdalene. This scenario is particularly unlikely, however, given the influence of the Church and the subsequently strict adherence to traditional renditions at that time. The more likely explanation is simply that Leonardo enjoyed painting good-looking men, and took advantage of every opportunity.
Leonardo's notebooks show many drawings of beautiful young men, often with cascades of curly hair and sultry eyes. Many of his more erotic sketches appear to show hermaphrodites or androgynous figures; one in particular, dubbed the Angel in the Flesh, shows a figure with a feminine face and chest, but with other clearly masculine features.
Beautiful Men
Leonardo's final painting, St. John the Baptist, was one of the few artworks that was physically in Leonardo's possession when he died; it was likely a personal favorite. The painting was created during Leonardo's last years in Rome, between about 1509–1516, and was brought with him to France. Contrary to usual portrayals, St. John (who is supposed to be living in a desert) appears in Leonardo's depiction as smooth and almost womanly in appearance. The long curly hair is a trademark of Leonardo's, and his beautiful face bears an enigmatic smile similar to that on the Mona Lisa. One of his hands appears modestly bent across his chest, while the other points upward in a traditional indication of the coming of Christ.
A sketch for a similar painting of Bacchus shows a figure with a comparable appearance to St. John. This naughty mythical figure is painted with the same pointing finger, same inviting tilt to the head, and a similar expression on his face. A difference, though, is that Bacchus is depicted as being sexually aroused. This detail indicates that, at the least, Leonardo had no qualms about depicting male sexuality.

The Question
So, was Leonardo gay or not? There is an undisputed lack of any documented relationship between Leonardo and a women; this fact, combined with his stated dislike for heterosexual relations, suggests that Leonardo preferred men over women. Further evidence is seen in his long-term relationships with two handsome young students. Of course, notions of sexual identity and terms such as “homosexual” or “gay” did not exist at Leonardo's time, and therefore it is difficult to place him into modern ideas of sexuality.

