Promises of the Bound

An eighteen-year-old, young man who goes by "Jonesy" to those who know him has grown so very bored of his stagnated day-to-day. The same repetitive cycle of sitting around the same boring home, interacting with the same small clutch of friends has lead to them finding some interesting ways of passing the time. Jonesy, though, never really bought into the whole "devil worshiping" thing from the start. It was more about a change of pace from the tedium.
Or, that's what he likes to tell himself.
Weeks of unremarkable attempts at summoning a creature from the underworld to do their halfhearted bidding come to a head on yet another dull, autumn evening with the arrival of a fire-haired "Princess of Hell" who goes by only one name; Etna.
Things quickly slip out of hand when she makes abundantly clear that her lengthy trip from home has a singular focus. A goal which only Jonesy knows full well the deeper meaning, and consequences, of, even if he is yet unwilling to admit this to himself.
His new companion, however, will ensure that he remembers every instance in which he sought her return from memories long since repressed, but not forgotten. When that reminder comes in the form of the Devil's adorable, young, millenniums-old niece, he finds himself unwilling to deny her promise to once again become his Everything.
They say that the Devil sees all and forgets nothing...
So does Etna.