Lu Bei challenged with provocative words, fearing that Xinli Monarch would evade a fight, even went so far as to mention his pants.
In reality, Xinli Monarch's robe was already destroyed, and his clothes and pants had been ruined by Lu Bei's brutal refining methods.
They were blown up.
But that's not the point, the ambiguity of the words seems to suggest some paid drama, sparking all sorts of wild thoughts.
For instance, the thoughtful Lu Zhou, She Huan with his environmentally friendly looking eyes, and Zhu Heng, who scowled at the thought of his own unfortunate daughter, were all led astray.
And then there was Xin Kuang Jun who was ecstatic with joy. He gave Lu Bei a nod, full of anticipation, impatiently urging, "Keep going, give us the scandals; when were his pants off, why were they taken off?"
Going by his reaction, one can infer his relationship with the others; at best it was average, at worst it was excellent.