Francesco Guicciardini said that when he was forty Lorenzo who 'was licentious and very amorous,' fell desperately in love with Bartolommea dei Nasi, the wife of Donato Benci, and spent night after night with her at her country villa, returning to Florence just before dawn. "Although she was not shapely, she was courteous and well-mannered."
Guicciardini further comments, "It is absurd to consider so important a man, with his reputation and judiciousness should, at the age of forty, be so taken with a woman who was not beautiful and already advanced in years." Bartolommea was thirty at the time.
While the above portrait is not Bartolommea (it's Portrait of a Woman Inspired by Lucretia, by Lorenzo Lotto, c. 1553), I'd like to think that she might have looked something like this, beautiful in spite of her size and years.
"Guicciardini gave credence to the report that the fatal illness of Lorenzo was brought on by the exposure to which Lorenzo subjected himself in following up his love intrigue with Bartolommea de' Nasi, the wife of Donato Benci, a lady who was neither young nor beautiful but of much distinction in manner and intelligence. In order to save the reputation of the lady, who lived near her villa in the country during the winter months, Lorenzo, then a widower, visited her regularly after nightfall and returned to Florence in the morning. He was accompanied on these occasions by a portion of that body-guard, with some of whom he was always surrounded after the conspiracy of the Pazzi. Two of them having complained of their hard service, the lady contrived o get them sent away in disgrace on distant embassies. 'A mad thing'..., says Guicciardini, 'was it, if we consider that a man of such greatness, reputation, and prudence---of forty years of age---should e so captivated by a lady, not beautiful and full of years, as to be brought to do things which would have misbecome any boy.'" (Smith, 1876, p. 134)
