To be honest, Guo Siyu wasn't too angry.
After all, she'd already realized that without Zhao Guang, her family would quickly be disassembled and devoured, with many eyes watching greedily. It was only with the power of Zhao Guang and those above him that they could barely preserve what they had.
So Zhao Guang could leave at any time, whereas her own family was utterly dependent on him.
Besides, such things were all too common, and Guo Siyu, who came from a notable family, understood this very well.
Not to mention others, even her own father had affairs outside, and did the family not know? They simply pretended ignorance.
In reality, her father was aware they knew, but as long as he didn't bring someone home, there was no issue.
When there's an imbalance of power between two families, one side always has to make some sacrifice. Some might give up a comfortable life, but no one would put their entire family in jeopardy.