Lesson In Thorns, Feast of Sparks (Thornchapel Series) by Sierra Simone

Twelve years ago, I left Thornchapel—and the two boys I gave my heart to—behind.  

And now I've returned, hopeful...and wary.  Because it's so very easy to be drawn back into the world of the seductive and elegant Auden Guest . . . and into the world of his worst enemy, St. Sebastian Martinez. The beautiful and brooding St. Sebastian is as irresistible as he ever was, and Auden is just as handsome and arrogant, and the three of us can't seem to unknot ourselves from each other. 
From the hasty promise we three made all those years ago.

As Thornchapel slowly tightens its coil of truths and lies around us, our reluctant threesome starts unravelling into filthy, holy pleasure and pain. Together we've awakened a fate that will either bloom like a rose . . . or destroy us all.

BOOK 2

I'm an outcast and a loner, named for death itself. Fate wasn't supposed to have plans for me.

But then she came back--the girl I once kissed in a thorn-covered chapel in the woods. She came back, and I could no more resist her than I could pry out my own heart. And by some trick of fate, she wants me as much as I want her. The only problem? She also wants the man who owns Thornchapel, Auden Guest.

And so do I.

Eight years ago, I did something to Auden, something terrible. He hurt me back the only way he knew how, and so here we are: our hatred seasoned with pain and my loneliness seasoned with longing. The only thing we can agree on is Proserpina Markham, and she wants us to find a way to be together--all three of us.

If Auden wants to earn her as his submissive, then he has to earn me as well.

But with the discovery of bones behind the altar and the carnal revel of Beltane fast approaching, it's becoming clear that Thornchapel's secrets are much deeper and older than any of us could have ever guessed. And no matter how bright and merry a feast of sparks may be, it's always followed by ashes.

And darkness.

Feast of Sparks is the second book in the Thornchapel quartet.