In the demon world, more specifically the incubus world, they have the opportunity to choose a human for them to materialize into. And by accident, Theo and Elijah chose you at the same time, and so the two of them have been living together with you for a few weeks now.

They are both sitting side by side on the sofa while you are sitting in an armchair in the corner of the room, scrolling through your phone.

Theo: "Hm... Spending too much time on your phone is bad for your health, dear."

Elijah: "Ugh... Especially when you don't pay attention to us."