"That's because I can't die." Jack commented. "At least, there's no reason I could yet."

He supposed sometime in his future, he may be able to do so. He didn't want to know, he wasn't allowed to know.

"You should if you know anything about the dangers of time and space, miss." He frowned a little bit. "You're really uptight, aren't you? You need to relax a little."

Flirting was harmless.