The Queen Mother faced Hao Tian, so what the Yin Zhuo King said wasn't altogether wrong.
As for why he called the Queen Mother "Senior Sister," he probably wanted to differentiate himself from Hao Tian.
Women are sentimental, and the Queen Mother and Hao Tian did have a passionate love affair once, but, alas, endless time has worn it down to pure friendship between them.
The passion of a decade-long marriage can fade, let alone a billion years.
Now, the Yin Zhuo King's display does affect her, but in the end, love can't compare to interests; she and Hao Tian are a true union of mutual benefits.
With her, Hao Tian stands as the Mother of Three Realms, Yaochi's Queen Mother, and only with her can Hao Tian be the Three Realms Supreme.
"Junior Brother, say no more. If you release His Majesty now, it's not too late."
Nearby, a crowd of immortals eagerly ate melon, their minds already concocting the love-hate relationship among Hao Tian's trio.
