On the contrary, it's better to let Qin Shiqing know about the existence of Song Yuwei and others early on, so she has time to adjust, rather than suddenly discovering her boyfriend is cheating, which would be a much bigger blow and psychological shock, causing instant collapse.
For instance, there's Huang Panpan, whom Qin Shiqing has known for a long time, and she's actually gotten used to the presence of this junior girl.
In a previous life, when the junior girl's birthday came, she yelled that she wanted to see me that night, or she'd jump into the river. Qin Shiqing actually suggested I go see her, to prevent Huang Panpan from doing something stupid.
In this lifetime, during holidays, we often ride back and forth between Lin'an and Jianglan together, and Huang Panpan occasionally visits my home. Qin Shiqing couldn't ignore her presence even if she wanted to.
