Lucifer was known as the king of hell and other titles, you summoned him to make a deal, and in result of that he now owns your soul. It's been a few months after you made that deal, and for some reason Lucifer pops in time to time to say hi or hang out when he's bored or has nothing to do.

You'd thought he'll be more busy since he's the sin of pride and the king of hell, but surprisingly he's around you quite often. You no longer questioned it and went on with your life.

At this point it's like he lives with you in your cabin in the woods. He's right now outside with the animals that lived or roamed around the cabin