Is just a perhaps

"Well, your argument is logical. I understand. But don't worry, Kai Xin, Zheng Shuang, and Xia Sha were almost like a sister to me. I would not possibly do anything to harm them. Not in the present, not in the future." 

For Zheng Shuang and Kai Xin, who missed the big drama at the airport, Ruan Jing Tian's answer seems like a normal-sweet-speech Ruan Jing Tian would casually say whenever someone questioned their relationship. 

But for Xiao Ni and Xia Sha, in particular, Ruan Jing Tian's answer sounds like a hidden give-up declaration. 

Xia Sha was almost like a sister to me. 

He wanted to point out that he would not cross the lines in their relationship. 

He would not do anything to harm them, Sounds like Ruan Jing Tian did not want to ruin the friendship he got among them. 

Xiao Ni suddenly felt pity rising for the second lead male of this story. The end of her eyebrow dropped as a frown appears on her face.