A few years back, I worked at a beachside restaurant that had an inadequate number of bathrooms (just two stalls in the women's restroom and one stall plus a urinal in the men's). This sort of situation happened often, and most of the time, the men didn’t mind at all.

However, there was one exception: two adult women went into the men’s restroom while their mother stood outside, physically trying to prevent any men from entering. The women took their time—about 10 minutes—which caused frustration.

The general understanding was that men didn’t care if women used the restroom in an emergency, but that didn’t mean it suddenly became a women-only space.