The Scum Is Heartless
Meng Gui immediately froze when he heard his question. He slowly turned and saw Shang He's serious face. He almost forgot. Shang He was hiding in his wardrobe, so he must have heard his and xiao San's conversation earlier.
If this was before, he would've told Shang He off for prying into his life. But, now, they have already resolved their conflicts. Meng Gui, also, could be said to have raised Shang He while Shang He was in a critical phase of his life determining what is right and wrong, so he knows Shang He isn't deceiving him right now, and he is asking him the question sincerely and not hiding any evil intentions.