I don’t agree (2)

"Oh this," Murong Si smiled at Murong Tai and replied, "This is something that Mother asked me to do. She said that we cannot lose in front of that mer who came from an unknown origin to suppress us. She asked me to wear the nicest clothes that I own and follow her. Since it was mother who asked me, I could only do as she asked." 

Though it was Murong Si who suggested this, Old Madam Murong agreed with him, thus even if Murong Tai was to make a fuss, she wouldn't be able to make Old Madam Murong change her opinion. After all, Old Madam Murong was stubborn and once she set her mind on something, she would definitely not change her decision. 

Thus, even if Murong Tai was to question Old Madam Murong nothing was going to come out of it.