Men only bars and dining rooms were universal in Saint James's clubs which allowed women to enter , aog, simply because only men could be members and women guests were permitted only in rooms designated for them, which, in the more liberal clubs, might include a mixed dining room. My point on discrimination is that now women must be given equal service.
My first two were classic. One had a dingy room, 'the ladies' sitting room' in
the basement, accessed via the area steps. At street level, there was a sign to it, which read "Workmen and Ladies"; workmen, such as the dustmen, were put first. That's the spirit ! The other had a sitting room at the back, with an entrance in a back street. When I arrived with a woman , and tried to enter by the front door, to get to it, I was refused with the words "No, sir, you'd be passing the members' reading room with the lady, and they might object"
The Carlton had a small, seated, area by the stairs, which was known as Cads' Corner because men sitting there could look up the women's skirts as the women went up the stairs to an area set aside for them.
And all had bars where women, if allowed in, would not be served.
And I do remember Ladies Only carriages on trains as well as Ladies Waiting Rooms.