@mateurdart is a French-language blog on erotic art in a wide variety of eras and styles. (NSFW)
Yaoi is a form of Japanese erotica "written by women for women readers", focusing on aspects of male-to-male relationships which otherwise tend "to make real gay men snicker." Still, gay men can and do create a wide range of erotic art within and across the yaoi genre.
Big Hats and Eroticism is just one of the many features of Tallulahs.com, an excellent site dedicated to images of the vintage nude. There's also lots of wonderful trivia and commentary, such as a brief biography of the Mante sisters (immortalized in the brilliant ballerina images of painter Edgar Degas), and the story of Liane de Pougy, convent girl turned runaway wife, turned celebrated dancer of the French stage, turned Romanian Princess. Or you can read about the mystery of H. Traut, elusive photographer of "the gentle eroticism of fairyland" whose images graced hundreds of postcards for several years until he seemingly vanished from the scene some time before WWI. Interested in drawing or painting nudes yourself? Here's a page of classical nude poses - studies in various categories that you can work from, including "The beauty of butts" and "seductive smoking"! Plus, you can peruse Tallulah's own art nudes, and a fabulous links page. NSFW, obviously.
"My hobby? It's funny you should ask... I make erotic carvings out of coconut shells..."
Erotic origami. Can you handle it?