"Yes, whatever. I've had an idea." Alastor raised an eyebrow, waiting for the King of Hell to elaborate with an impatient air about him.
"We do not tell a soul about this."
Or
Alastor and Lucifer have a secret relationship. No one knows about it; until they do. When Vox plans to expose their love, the feuding couple are forced to call on old friends, a few enemies and Lucifer's daughter to save their own necks.