NC for this one as I'll definitely be outing myself. I'm a library assistant that runs a fortnightly sensory play session, I do this because I love to, because it's an important part of child development and because I know I would have loved something like this when my DD was a preschooler. I pay for most materials out of my own pocket because our library budget doesn't allow for it and for the most part I can reuse materials.
Apart from today that is. One of the children completely ruined everything for late comers and that's never happened before, they essentially just mixed everything together (sand, rainbow oats, water, paint, shaving foam, playdough. Everything. All of it.) in a sensory play tub and them dumped it all out on the library floor. While all of this was going on the mum was sat there absorbed in her phone and chatting with the other mums, not interacting with her demon child at all. None of the other kids got to enjoy anything I'd set up and while I appreciate that I'll have to clean up a bit of mess, this was ridiculous. Nothing can be reused and my librarian has said that if it happens again then no more sensory play, all because of one selfish mum that views us like glorified childminders instead of as the people that facilitate her to enjoy this experience with her child.