How and when did Gu Yi know his identity?

thousands of miles pass by, but it's very well hidden. I look at Gu Yi coldly.

Gu Yi looks innocent. It seems that he found out what he didn't know. He immediately slapped himself and explained, "no blame for Rong Jing, Qin Chuan. Don't get me wrong. The last time you quarreled with Rong Jing at Rong's house I'm on the side, you You take out a dagger and send it to Xiao silently. Have you forgotten? "

at that time, Baili QianChuan asked Rong Jing to settle accounts, and Gu Yi protected her as her husband. Unexpectedly, Baili QianChuan showed...