Michelangelo vs Leonardo
Michelangelo and the older Leonardo did not like each other. There was a famous encounter in Florence in 1503 when Leonardo voted for Michelangelo's statue David to be placed inside, instead of outside, and this reportedly enraged Michelangelo. The statue did go on display outside in 1504 replete with fig leaves covering the controversial parts, which may have been at Leonardo's suggestion. In the long run, Leonardo won out - the statue was moved inside and a replica stands outside. The fig leaves are gone.
For his admirers, Michelangelo's sculptures represent ideal beauty, ideal heroes - like David - wrested from brute matter in virtuoso displays that reveal the divine. Michelangelo believed that art should be hard, physical, tense and muscular, difficoltà , terribilità , yet indifferent and aloof, throwing out a challenge to the viewer. For his critics, and we can include Leonardo among them, Michelangelo was describing himself and maybe his sex life, where things could get a little rough. To Leonardo, these statues represented self-righteous and pompous Florentine nationalism.
Leonardo's most famous dismissal of Michelangelo was the "sack of walnuts" jibe at the muscle-bound figures like this one (below) of Eve on the Sistine Chapel ceiling. It seems likely that Leonardo would have checked them out when he was in Rome. In 1514, he surely had Michelangelo in mind when he wrote: "O anatomical painter, beware, lest in the attempt to make your nudes display all their emotions by a too strong indication of bones, sinews, and muscles, you become a wooden painter."
The model for Eve would have been male and the breasts added. In typical Michelangelo fashion, there is implicit sexual inuendo in "her" juxtaposition with Adam but, after all, that's why they were thrown out of Eden. Full image here.