WordNet sense 1 (capable of being reversed or used with either side out):

reversible, two-sided

WordNet sense 2 (marked by deliberate deceptiveness especially by pretending one set of feelings and acting under the influence of another):

deceitful, double-dealing, duplicitous, two-faced, Janus-faced

WordNet sense 3 (deceptive or fraudulent; disposed to cheat or defraud or deceive):

dishonest, dishonorable