JAck was looking at her. He kissed Caitlyn more and grinned "Yup." He was happy he had met her and kept his arm around her. He was wondering too how long the Master could have been here.
He waited to see what the Doctor would say.
"We'll we can make ourselves appear human and think we are human, But I don't think thats it, because hes clearly been planning something while knowing full well who he is. I don't think hes been here that long. The Master is clever."
He knew the Master would have done alot to have got this far.