Tom Zoellner comments on the non-mating ritual that takes place when two heterosexual men meet at, say, the Holiday Cocktail Lounge or Hi-Fi: someone must raise a giant flag that says "Don't worry, bro: I don't crave cock."

The Straight Sign is flashed in a variety of ways, but they almost always involve the sudden invocation of women. Cocktail servers and bartenders are a common prop. I've heard "Damn, she's hot" more than once — even in reference to a not-so-hottie — just so the Straight Sign can be dispensed with quickly and the subject not belabored.

Aww, it's cute to see the men try and communicate using their words.
There's No Gaydar for Heteros, but There Are Straight Signals [Black Table]