Han Bohai had no answer for her. Because he knew if she was given another chance, Chen Xiu would still choose to save Liu Nuan's life. Even if she knew what the other would do to her, she'd still not go against her conscious.
"Can you both stop it?"
The intense staring session between Xiu and Han Bohai was only broken because of Darren's voice. He looked at both of them and said clearly, "I don't want either of you to repeat it!" He knew what kind of effect all of these reminders could do on Xiu and yet she was looking for an argument on purpose.
However, what he didn't realize was that even if he managed to notice something strange about Han Bohai, how could she miss out? She was someone who was most familiar with him. And she had already noticed that the way he looked at her was different. She knew it was a wild shot but she believed that Han Bohai knew she was Chen Xiu.