Her Tortured Beasts by E.P. Bali — book slip

I've surrendered myself to my father and the beasts who would pay to own me, all to protect my friends and my mates. But I never expected the one mate who resented me the most, Xander Drakos, a hateful dragon with a cursed heart, to betray me so brutally. Now, chained and bound, he escorts me to Drakos Estate, where horrors await. Yet, Xander's dragon isn't happy with what he's done, and unexpected alliances may form.

This is the fourth book in the Her Vicious Beasts series, a New Adult MFMMMM contemporary fantasy romance. The heroine has five fated mate love interests that will eventually form a bonded group. It is medium burn with 18+ spice starting from book 1. Each book ends on a cliffhanger but the series concludes with a HEA.