Xiao knew that arguing with his mother wouldn't lead to anything. In truth, he wanted to tell her everything, truthfully without hiding anything, yet he couldn't. Not because he didn't trust her - if he couldn't trust his mother, then who could he trust? - but because he didn't want her to be embroiled in whatever was in store for him.
Telling her the truth would connect her to both his fate and the lines of Karma. This was not something Xiao desired. In a world where danger lies hidden and secrets are chosen, he couldn't guarantee that he could 100% protect his mother. For that, one needed one's own strength; nothing other than that was better.
Plus, he knew that his mother wasn't some pretty vase that needed protecting. She was an independent and strong woman. She didn't need his protection; he just needed to provide her the stage for it. He was sure his mother would excel. All Xiao was waiting for was a chance. The moment 'it' came, he would make his move.
