Betrayal by the Demon Lord

Emily is married to a demon lord who kills without blinking. On their vacation, a catgirl waitress named Rosa sets her blood on fire.She knows one wrong move means death. But Emily can't stop teasing Rosa right under her husband's nose. Rosa plays along at first — then Emily's touch breaks her down, again and again. One night, Rosa climbs into the lord's bed, with Emily and her murderous husband right beside them.