Tangmo truly deserves to be the person who has been by Luo'er's side the longest—she even knows about these kinds of things. Or rather, after years of companionship and intimacy, Luo'er has virtually no secrets in front of her and has even started to bear traces of her influence.
So she is well aware of Luo'er's boundaries and weaknesses, as well as his inner struggles. Otherwise, she would never have encouraged Baiyue to boldly confess her love.
"Why do I understand Luo'er so well? Because I like him, I want to be with him forever," Tangmo tilted her head, a dreamy expression gracing her face. She seemed to be reminiscing as she muttered to herself, "I still remember the first time I saw him; it was at the academy. Back then, he was like a star descending from the mortal realm, dazzlingly radiant. Even someone as thick-skinned as me didn't dare approach him easily. I could only silently watch him from afar, paying attention to his every joy, anger, sorrow, and happiness..."