Given Fay's fingertips tingling brightly on this skin of his collarbone, it seemed pretty clear that Fay did know. Kurogane looked at the little vampire out of the corner of his eye, and was met by a soft and surprising expression.
Yeah. Fay knew, all right.
Suddenly he was very aware of naked skin against naked skin under the pool, and of the cupid's bow of Fay's mouth.