Because speaking up was pointless.
What she did for him in the past was genuine, without any hidden agendas; she should have realized that there was no possibility between them, and therefore she wouldn't have had any expectations.
Even if she still desired to be with him, she shouldn't have rejected him on the cruise ship.
Without a desire to be with him, she would not have said those hypothetical words trying to keep him...
In short, Jian Yufei had many contradictions.
She likely hid something from him.
...
Perhaps, her causing him to go to prison had a reason, or perhaps, their child... was still alive...
Ruan Tianling thought of the child's unmarked grave!
Jian Yufei said that not engraving it made her feel as though the child was still alive, not dead.
At that time, he believed her words and didn't think much about it.
But now, thinking about it, he sensed something was off.
