disingenuous, artful -- (not straightforward or candid; giving a false appearance of frankness; "an ambitious, disingenuous, philistine, and hypocritical operator, who...exemplified...the most disagreeable traits of his time"- David Cannadine; "a disingenuous excuse")
artful -- (marked by skill in achieving a desired end especially with cunning or craft; "the artful dodger"; "an artful choice of metaphors")