I'm sure the bus company could dig out some CCTV...
Our family is ostensibly open and honest, but I realised recently that my mother is carrying on her mother's system of not saying nice, or otherwise, things directly to the offspring concerned, but via another offspring, thus engendering competition and insecurity. I have grown tired of this PA nonsense, and have said a few things directly to her, or sis, and feathers have been ruffled.
HB MI - maybe your DC could go with DP to tai chi. After all, how hard can it be looking after two children when you're supposed to be doing something else??