Lu Yizhou took a few seconds to regain his bearings. It wasn't impossible for Terra to hear his conversation with 666. Afterall, a bonded sentinel and pair would be able to sense each other's emotions and thoughts. From the original plot and Doctor Wyatt himself, Lu Yizhou learned that the higher their index of compatibility was, the more compatible their souls and bodies would be. Judging from how high his compatibility with Terra was, it wouldn't be weird if someday they were able to share visions with each other.
However, his reasoning was immediately denied by 666, so fiercely to the point that the system almost screamed right beside his ear.
[666: NOOO!!! T—That is not possible! The simulator itself is equipped with privacy settings that will shield our entire existence from the characters. It's impossible for him to notice our existence, Host! This—This is not logical!]