Nana knows what Veer means. Because he's here now. Act as the only son of Ryouta and hers. He was taken care of by them since returning to Netherlands again. Stop bothering Renji's life, and start growing up to Ryouta's expectations.
Nana knows Veer's efforts all this time. Since leaving Renji's life, the man had never played with his future. He spent his time spurring himself on. Finished studies, got a promising job, went on several blind dates suggested by Ryouta—with girls, of course—but because he always refused anyone who came, Nana now knew what the problem was.
"You know it's been 17 years," Nana said. "Mama is quite grateful you've looked after Renji all this time. But if he really has chosen the latter, are you going to let him go?"
"...haha," laughed Veer. Suddenly he looked really sick. "What am I supposed to do? Father won't be happy if I do something wrong again."