It's one of those plays that kept popping up in the 1950s, when you couldn't talk about gay people openly, so you threw in as many hints as you could.
The hunky Hal shows up in a small town that's busily preparing for the annual Labor Day Picnic. He takes off his shirt.
This is the 1950s. You never see bare skin.
Hal gets naked with Alan, has sex with Madge, and flirts with everyone else, but in the end he leaves, leaving everyone blinking in surprise and asking themselves "What just happened?"
In the original 1953 production, Ralph Meeker played Hal, and newcomer Paul Newman played Alan.
It was filmed in 1955 with William Holden and Stuart Whitman (top photo), in 1986 with Gregory Harrison, and in 2000 with Josh Brolin.