Accidents happen - and as any parent with a toddler knows, that can be at any place and time. A mainland couple found that out when their two-year-old just had to go as they were shopping on Mong Kok's busy Sai Yeung Choi Street and there was no toilet close at hand. With two options - one of letting the child humiliatingly wet his pants, the other to allow him to pee in the street - they chose the latter. In any ordinary city, there would have been a few disapproving stares and that would have been the end of the matter. But not in Hong Kong: Amid jeers and shouts, two passing men took videos, the embarrassed mother grabbed for the camera, scuffles broke out, police were called and the images have since gone viral on the internet. What was a trivial incident became an international news item.

Online opinion has been polarised, with people split as to who was right and wrong. State media understandably felt obliged to weigh in. Once again, mainland tourists had been painted in a poor light, in part due to the discrimination towards them by Hongkongers. A commentary in the overseas edition of the said parents and young children have to be treated sympathetically where calls of nature are concerned. Rightly, it advised that both mainland visitors and their hosts need to be more understanding and civil.

Hostility by some Hongkongers towards mainland tourists ceased being civil some time ago. Tolerance also is wearing thin beyond the border, with a threatened campaign for tourists to come to our city with their children and have them urinate in the streets. That is escalation, to be sure, but it is also against the law: Parents are liable to be fined up to HK$2,000 if, without reasonable cause, they let a child under the age of 12 "obey the call of nature in any public street". Everyone should calm down. There is no perfect solution when parents have a "got-to-go" toddler on their hands. Preparation is needed - a change of clothes for the child. Also required is an understanding of customs and laws and tolerance on all sides.