I'd just picked up DS1 from school and was on the way out of school, when the little brother of one of DS1s classmates whizzed past on his scooter.
We were in a passageway, so his mum and big brother were not in sight, and the speed he was going it was perfectly possible he could be round the corner and out of the gate before they appeared, so I called in what was supposed to be a friendly way "You're going to wait for your mummy, aren't you?"