On the subject of bogs, any traveller on East Coast services has probably heard the "attention traincrew; disabled passenger alarm operated" announcement hundreds of times!
I was about to have my ticket checked once when it went off; the guard sighed loudly and said "Excuse me, I'm just going to explain to some embarrassed person where the flush is". On another occasion, during severe disruption, a train was at a standstill outside a station for about an hour, all passengers standing, the announcement sounding every few minutes. The guard did an announcement to the effect that he couldn't get along the train because it was too busy, and if somebody was actually in danger, could they pull the communication cord.
I've only ever had one dodgy experience with train bogs, which was some point in 2015...
A friend and I were on a CrossCountry Vomiter, a 220, I think, but anyway, we were having to stand as the train was busy enough to leave no seats within the adjacent two carriages. My friend and I split up, my mate went to find a seat, me to go to the bathroom. At the time I opened the door, I saw something I really didn't want to see...A couple having sex! I think my only reaction was "Wrong door!"
I still remember the incident as the "Aisle High Club", in reference to the well known aviation club...
I once heard about a couple who were caught
in flagrante in a toilet in a public building, the member of staff finding them was not sure what to do.
As such, in the next staff briefing, advice was issued - "If anybody comes across people having sex in the toilets, please let security know". Only having said it, did the person realise what they'd said...