C330 Mother and Child Meeting
The reason why Gu Yanci called her before class was because he didn't want her to come too early, but also because he didn't want to worry her.
If his teacher had told Mrs Liu that he didn't attend class, she would have surely gone crazy with anxiety and might even call the police.
Gu Yanci immediately comforted her, "It's not Little Yin, it's Big Brother