I was there 1977-8. There were two F&C students who were brothers; their rooms were just along the corridor from my room in the west wing.
I was married and lived in the Mess during the week but went home to my in-laws most weekends. One Friday evening I had to stay over for some reason, probably a formal dinner night. I went into the ablutions room and the shower cubicle, which was actually two adjacent, open shower cubicles with a dividing wall between them, they had no individual shower curtains. The small changing area was common to both, with just a slatted bench and enough room to stand. The shower curtain was at the entrance end of that space. As I went in, there was someone in the far shower. As I began lathering myself up the other person finished showering and came out into the common space to get dried. I was expecting to see another student but instead an extremely attractive and curvaceous, long haired and nicely tanned brunette female appeared, stark naked. I’m no prude, but to say I was taken aback was an understatement. It was an all male ablution room. I didn’t know where to look but she was totally unabashed and simply gave me a big smile and said “Evenin’!”
She briefly dried herself, wrapped her towel around herself and departed. I couldn’t resist waiting ten seconds then nipping across to look out of the main ablutions room door to see where she went. She went into the F&C brothers’ room. Turned out she was a common visitor at weekends and was a professional lady who was paid for her services.