Why he was so shy?

Qiu Mu gripped the bamboo slip in his hand tightly when he heard Kang Cha Ying run away from her house. He threw it toward the soldier, who caught it. Without thinking for another second, Qiu Mu left for the Kang residence to find out what exactly happened. 

He pulled the reins on the horse as soon as he arrived at the Kang Residence and ran inside. 

"Where is Kang Xi?" Qiu Mu asked, grabbing the collar of the servant, whom he saw first. 

"Lord Kang is in his room," the servant replied. Qiu Mu let go of his collar and marched toward Kang Xi's room. Somewhere, he had the feeling that Kang Xi did something which forced Cha Ying to take such a decision. 

The servants were confused to see Qiu Mu, but they did not stop him. The grim look on the second prince's face had terrified them.