"don't stand on the seat, Mary, you'll fall when the bus goes round a corner... don't make me say it again... *bus goes round corner; Mary bangs chin and cries*... I told you so; when will you learn?..."
The child does learn. She learns that buses make unpredictable lurches and that her parent won't help her learn how to balance safely. She learns that her mother is not interested in helping her achieve her goals, but is bent on thwarting her and then gloating when she does not succeed alone (with the smugness of being proved right).
"Shall I hold on to you to keep you steady so you can see out of the window?"
"Shall we slip your shoes off so the seat stays clean?"
or, even better,
"Let's pop this small rubber-non-slip bath mat under your feet so the seat stays clean AND you don't slip")
or just quietly 'spotting' the child without comment so if the bus lurches they don't bang their chin.
I wish I lived in dreamland.