"Seriously?" The Master couldn't help but be amused by that. "The little minx! My Lucy back home has been very - tolerant - of me and the Doctor, but she's never shown much interest in him. She's more interested in Jack, I think. The immortality thing fascinates her."
He'd have to watch her, when he got back. Or possibly encourage her. Oh, what a way to completely confuse his Doctor back on the Valiant!