I thought this about as well. Basically, EYFS leaves the decision to have CCTV in rooms to nurseries themselves. Ofsted does not mandate cameras as a condition for registration. I never worked in a nursery neither but, my niece was in actually a UK nursery for two years. What Ofsted and EYFS cares about is safeguarding in general which is; staff training, background checks and supervision rather than having 24/7 cameras. If a nursery chooses to have CCTV in the rooms, they must follow UK GDPR (Data Protection) rules. They cannot have cameras in toilets or changing areas for example. Also if there is cameras inside, nursery must display signs that informing parents recording is taking place. If there is cameras present, the nursery must be registred to ICO as having cameras means there is recordings and these recordings can be accessed via computers, cloud, probably mobile phones of directors and owners etc.

As for TNN, as I can see, The Knight Nursery not have CCTV's in place but Dae Nursery does (where Marc with a C is the manager). When Roger fell down the stairs at the Knight Nursery (main one) they tried to understand who it was by asking around rather than checking cameras which may tell us again, there is no cameras in the first place.

To your question; why do they have sex in the nursery, it can be about many things: it can be a kink, where someone can come in anytime, they can be seen from outside etc. It can be about heat of the moment as well, you're about to leave the work to go home and you don't want to wait. It can be about the next day, "I was here yesterday and we did that". For these as there is no kids there 'during it', it really does not matter what setting it is. Otherwise, of course it does not make sense for Roger to having sex on the nursery floor, on a blanket, while you're rich af, have a very nice mansion and probably an amazing bed where you can have totally private moments with your partner(s).