Heartless Boys Never Kiss is the fourth book in S.J. Sylvis's St. Mary's interconnected standalone romance series, focusing on a best friend's brother and enemy-to-lovers trope. The story features Sloane White and Tobias navigating dark, shared traumas, with the plot hinging on their forced proximity during tutoring and the brewing suspense of anonymous threats. It is available in various formats including ePUB (Kindle) and Paperback .