"Two wizards walking into a bar could be a good start to a naughty film too," he teased sarcastically. But it was deflection, because he didn't consider himself a wizard. He dabbled, but he was never...any time someone tried to label him it backfired on him. He wasn't worthy of a lot of the names people tried to give him, let alone the titles.
He grinned, because he understood some of the things Dresden was saying, but he'd ask about foci later. "I'm not a threat to you," he assured the other man right away. John was an enemy of a lot, but usually the sordid sort. This man seemed...well, his magic didn't feel bad. But then again, while it was difficult to con a conman it wasn't impossible, so Constantine was ever cautious in some ways. Never mind that the man looked a lot like two of his friends' father to top it all off. "Didn't mean to out you to imply I was," he added. An apology of sorts. He sometimes--okay, quite often--forgot not everyone liked their magic being noticed.
"Elemental is something I'm familiar with but I..." And John paused again. How to explain without revealing what a true git he was? Ah, hell, might as well be honest for once, yeah? "I've borrowed from a lot of walks of magic over the years. Soddin' easy to get mixed up in the lot of it once you get started."