Why the productions that don't have any obvious gay content? Because you never know when a director or is going to call for a theater hunk to take his shirt off, and the beefcake is more intense and immediate when it's live.
Of course, you might have to deal with actors gushing at each other that everyone on Earth longs for hetero-romance, that the Meaning of Life lies in men and women kissing, but you hear that a thousand times a day anyway.
Here is a random assortment of 10 stage plays that yielded unexpected beefcake.
2. Unity(1918), by Kevin Kerr, is a favorite of university theater departments in Canada. It's set in a small town in Saskatchewan during a flu epidemic, with a soldier returning from World War I involved in hetero-romance.
The Boy was played by a nude David Burtka (now married to Neil Patrick Harris).
More after the break.
8. I'm not a big fan of Sam Shepherd, but at least soapster Jake Silbermann unbuttons his shirt for True West, about two brothers, one a politician and the other a thief.
See also: The Best Little Whorehouse in Texas; and Tarzan: The Stage Musical.