Shen Biran's fondness for Si Yuchen is enough to illustrate one thing: she supports the validity of the marriage between Si Yuchen and Gu Xiaonuan, and is on their side.
Shen Biran's words made Si Yuchen more uneasy, as the feelings between him and Gu Xiaonuan were not pure, and from the beginning there were self-interests involved, not a marriage united for love.
"I know, Elder Si's methods are very familiar to me. The woman you like must also have his approval. If he disagrees, then your relationship won't go smoothly. Even if in the end, you're no longer part of the Si Family, no longer his grandson, he won't let you have your way. Your relationship must be one that he agrees with and supports."
Shen Biran understood Si Lingtian better than Si Yuchen did; Si Lingtian's iron-handed methods wouldn't give his grandson any concessions either.