Fred and Carl both waited for Vincent to answer. And as of this moment, Vincent would love to drown his nosy cousin.
"Son?" Fred is anxious to hear about his mysterious trip three years ago that Carl brought up. He has a feeling that it is something important for Vincent.
Fred has just seen it clearly. A lot of facts he didn't know about his son. He was confident not to check on him before, as Vincent was always on his side since he was a teenager to understand how to manage their company. And he didn't see that Vincent acted strangely. He showed his enthusiasm to learn and creativity in designing since he was young.
Also, Vincent is a good son; he worries less, showing how responsible a person he is. But he was wrong. For all of Vincent's life, he didn't ask what he felt about everything that happened in their family.