"Delay no more" comes from Cantonese foul words with similar sounds (Diu lay lo mo), which means "fuck your mother".
Seldom used seriously and speak in verbally. "Delay no more" appears in writing as joke among Hong Kong people. A fashion brand in Hong Kong produced T-shirts with "DelayNoMore" on it and advertised it on large billboards.
To express non-serious anger in writing, in chat room or on message board. Write "Delay no more" in reply.