As for why he didn't call him "brother-in-law," the main reason was that it was still too early for that, calling him "brother" was more appropriate.
When Mei Mengchen's eyes slanted, he saw Pei Ziyu sitting beside her and noticed that Pei Ziyu seemed to be looking at him too. He wasn't afraid, and began to seriously size up the other person.
It had to be said that in terms of appearance, Mei Mengchen was quite satisfied with him. He didn't have a wide social circle, but in the one he had, nobody looked better than him. So, grudgingly, he could be considered a match for his sister.
Moreover, they had spoken on the phone, so there was some familiarity. Pei Ziyu took the initiative to speak, "Chenchen, do you remember me? I'm the Brother Pei who often calls you."
"I remember." Mei Mengchen nodded earnestly to show he remembered.
Pei Ziyu, delighted, immediately handed over the toy he'd chosen, "This is a gift from me, I hope you like it."