Within the same vein as conniving, we've got duplicitous [duˈplɪs.ɪ.təs] - deceptive and fraudulent (Merriam Webster) As an example, here's a gem of a quote by Ianthe Tridentarius: "If God hears that yet another one of his duplicitous sluts betrayed him, he’s never going to come back from it”. (Nona the Ninth by Tamsyn Muir)