Well, Jack always has been drawn to the darker side of his partners, to the things that make them bad boys or girls. He still doesn't really understand how hard Spike's trying to put all that aside, or why - how hard it is for him to keep that balance.
"Absolutely all good!" He glances around, somehow certain now that he's not going to be hearing any Daleks approaching. This is a new dream, now. No longer a nightmare.
Then he lifts an eyebrow. "Do you know, I think this might even be the exact spot where they exterminated me! Talk about subverting bad memories!"