Make that an incredibly well-spoken Dragon. Jack nods so much he bows slightly with the motion. In all the stories about dragons, names can be arcane secrets. For a second, he mentally kicks himself for asking her name so casually, but if she's willing to share, he'll listen.

"Of course. If you need me to swear on something," hunh, what does Jack Harkness consider sacred? "On the name of the Doctor, I'll keep it a secret."

"If you don't wish to reveal it, I won't be offended, but I at least need something to call you by?"