Disclaimer: Nothing is mine. And before anyone protests "But they're brother and sister"…this is Delphine we're talking about. Her interactions with Dio just aren't very, um, sisterly.
It's not as if he enjoys it.
Quite the contrary.
It's just that he can't escape it.
Because no matter what, it ultimately comes to this. She makes an innocent request for him to come to her chambers, spurs him on into a fight, and then somehow—though he'd be damned if he knew how—it ends with the two of them in bed, the sheets stuck to their naked skin, each breathing heavily. And in the end, he knows he can only blame himself for this. After all, if he had refused her request…
(Oh who was he kidding, anyone who dared refuse Delphine's requests had a tendency to dissolve into "pretty little snowflakes" as she put it.)
If he had just kept his mouth shut, they might not be here.
Or at least, that's what he tells himself.
He lies back and closes his eyes. His thoughts fly to his dear butler and he wonders if this would be any more enjoyable were he here.
"Lucciola," he mutters, quiet enough for no one but himself to hear, "If you were in my sister's place…if only…"
And so the next time it happens, the next time she grabs him by the arm, the next time they're flung onto the bed, he imagines another on top of him. And then it becomes, oddly enough, enjoyable.
And then he makes that fatal mistake of crying out Lucciola's name just as the two reach their climax.
And oh boy, does she make him regret it.
Naturally, Lucciola is called in the next morning and punished alongside Dio.
Naturally, both walk in agony for the rest of the day.
And naturally, Delphine and Dio end up in bed once more in the evening.
"Aren't I good enough for you, Dio dear?" purrs his sister. "Whatever would you need him for, hmm…? Perhaps I should call him in and ask—"
"No, wait! Don't…"
His voice is drowned by her mouth clasping over his and he falls back onto the bed. At last, she separates, and whispers:
"I love you, Dio dearest. You know that, don't you?"
It's the way her voice drips with syrup, the way she says it so playfully, teasing, meaning it but for all the wrong reasons, that causes him to shudder and curl up on his side of the bed.
"Well, good night," she whispers, with a flick of her tongue against the back of his neck.
He does not answer. Instead, he only thinks:
Good night, Lucciola.