A bond mark

"Amelia, you also have the same mark on your back as me," he whispered. 

"Really?" I asked, surprised. 

He hummed, wrapping his arms around me and hugging me from behind. "It's beautiful, just like you said," he whispered as he kissed my shoulder. 

I nodded, but several questions were swirling in my mind. What does this mark mean? Why did it appear on our bodies? And what does it represent? 

As I wondered these questions, I heard the devil's voice speak in Killian's mind. 'Killian, I think this is the bond mark....' he suggested.

"Bond mark?" I whispered out loud, confused. "What's that?" 

"I'm not sure," Killian admitted, his voice hesitant. "But I think after… after last night, this mark appeared. It signifies that we are one — that you are my partner, my mate." He paused, his tone laced with an emotion I couldn't quite place. "I think it might have something to do with my identity as a devil."