Having entered Peicheng, Su Wenyue had familiarized herself with the local conditions and collected quite a bit of information to interact with the official families' female relatives, which was indispensable for backyard socializing. Particularly for the situation at the City Lord Mansion, Su Wenyue had done her homework and gained a basic understanding, and so had Xiao Xi, who shadowed her.
Observing the pair of master and servant, Xiao Xi became even more convinced of her guess, and thus her tone grew less polite. If this master and servant had been more courteous, she naturally would have upheld a servant girl's duty and not have readily offended anyone, after all, they were now on someone else's turf. But it was clear that the pair had come looking for trouble. A passive response would only invite others to think they could bully our lady and take even more liberties.