Deimos looked confused at what hecate said, looking at the cat like he didn't understand the concept when applied to his new pet, like he didn't understand the concept at all; when Daddy had... 'died'... he'd disappeared, and the cat hadn't disappeared, thus couldn't be dead.
Right?
He took a hesitant step back as she stepped forward, looking back over his shoulder like he was readying to bolt. He snapped out of it in the next instant though and rubbed his thumb over the dead cats head, looking at Hecate's outstretched hand like he didn't know what to do with it. "I was lying, he isn't rude." he said, as if showing that it was a good pet would mean that he would have permission to keep it.
As the dark goddess reached out and cleaned his face, Deimos wrinkled his nose the way a child would if it's mother licked her thumb and rubbed a smudge from it's cheek before he pulled back a little and put his thumb in his mouth, biting not sucking and knocking his chin against the cat's body as he'd lifted the digit on that hand. "I wanna keep him." he said childishly stubborn.