Have been reading up HK news and noticed that the hostile
relation between the two has lately been on the news (not in Sg)
and all over the net.
It started off with a PRC family taking a MTR transport and a
mother let her kid eat in the train. See the video from
youtube:
A PRC professor (who claimed to be Kong Zi's descendents but was
revealed that he was an abandoned baby), in his response to the
above video started referring the Hong Kongers as dogs: (with English &
Chinese subtiltes). Note: he also insulted
Singaporeans (at 6:05), implying Singaporeans behave because
of law and order, not because Singaporeans have good
characters.
Subsequently, there have been articles, FB, demanding this
professor to apologise to HKers. The long time disgruntled
Hong Kongers even came out with this poster ad: (picture from
Temasek Review FB)

And guess what? The PRC retailiated with this poster (see
below), telling ppl in Hong Kong that Mainland China is the father
and Hong Kong is the disobedient son:

Very fierce fight... to be continued...heheheh.