Painter George Bellows depicts a day at the seashore in “Beach at Coney Island”: shirtless boys, a passionate couple, and girls in white bathing attire, all in close quarters at the city’s tawdry summer amusement playground.

Suggestive, sure, but it’s hard to believe that the painting was considered vulgar by critics.
“His Beach at Coney Island (1908, private collection) signals the relaxed moral codes associated with this locale on Brooklyn’s south shore,” states this page from the website of the Metropolitan Museum of Art, which included the painting in the big George Bellows show from 2012-2013.
“One leading critic described Bellows’s teeming view as ‘a distinctly vulgar scene,’ not least because of the amorous couple shown embracing in the foreground.”