His widow, Catherine Sack, said: “I don’t know how good or bad Hockney’s teeth were, but he obviously visited him a few times.”
She added: “Brian was a very good dentist. He was just appreciated… He was very interested in art and he had a lot of artists, having the surgery where it was… He was into the arty world. He did a lot of famous people like the Duke of Westminster. He was a very trendy dentist.”
She recalled him describing Hockney as “a very pleasant, down-to-earth guy”: “Brian really appreciated that because he’d get some people who… were more showy. But [Hockney] wasn’t.”
Inscribed ‘Powis Terr’ and dated Sept 1967, the pen and ink sketch measures 19.5” x 12.25” (49.5 x 31.1cm) and is estimated to fetch between £30,000 and £40,000.
It depicts the artist’s then-partner Peter Schlesinger in the nude. Hockney was teaching a summer class at the University of California in Los Angeles when he met the then 18-year-old student, who was 10 years his junior.
They began a long affair. Schlesinger often modelled for the artist and appears in some of his early works, including Portrait of an Artist (Pool with Two Figures), which sold for $90m (£70m) in 2018, breaking the auction record for a living artist.
Lover and muse
It shows Hockney’s former lover and muse standing beside a pool with a man who might be the painter’s new boyfriend swimming underwater. Hockney had already started the painting when they broke up in 1971.
Asked why she is selling the sketch, Mrs Sack said: “I’ve loved it. [But] I’m partially sighted… a gradual thing… I can’t appreciate it as much as I used to because of my lack of sight. So I would love someone to love it as much as Brian and I did.”
She added: “It’s never been on the market before. David gave it to Brian and it’s never been out of the family or been seen anywhere.”
This drawing bears a label of the Kasmin Gallery, one of the first to exhibit Hockney’s work, which closed in 1972. There is no record that it was exhibited there.
Offered for sale
It will be offered for sale on May 9 by Parker Fine Art Auctions in Farnham, Surrey.
Henny Smith, its director, said: “Schlesinger was used as a model and a muse quite a lot. It’s recognisably him in this drawing. It’s quite ground-breaking, a male nude like this. Such simple, but sensitive lines. It’s beautifully and effectively done.
“Depictions of male nudes were done in Greek and Roman times and then the Renaissance, but it was unusual to have something this bare in the 1960s. You can see the romantic nature of it in the way that it’s been done. It’s just a lovely work. There are a few Hockney nudes, but not many.”
She added: “The fact that this has been in a private collection since it was given is so wonderful.”
Mrs Sack is also selling “Six Fairy Tales from the Brothers Grimm”, a signed copy of Hockney’s miniature book of etchings, which is estimated to fetch between £500 and £800.
The Telegraph approached Mr Hockney for comment.