"Hello, Balthazar. This is Aziraphale. It's come to my attention that Lucifer, one that is not from your world, nor mine, has been visiting the Nexus. I've already let Crowley know, and I wanted to give you warning as well."

A significant pause follows.

"Apparently, Lucifer has been... fraternizing... with an angel in the Nexus. It isn't me, obviously. Would you happen to know anything about this? Please get back to me at your earliest convenience."

Click.