Jiang Wanyin and Wei Wuxian
His little brother could duck his head all he wanted but that didn't mean he hadn't caught the action. Hadn't caught the pinkness to him. Maybe it'd be harder to see in the dark but it had definitely been there. So, when his brother tries to deny it, he laughs.
"Aiya! There's nothing wrong with your cheeks going a bit pink at the idea of the First Jade."