Wiktionary
over-polite
a. Excessively polite.
Usage examples of "over-polite".
You can see the same performance take place practically any minute on any city pavement when two over-polite people, each bent on giving the right of way to the other, side-step with such maladroit effectiveness that they succeed only in blocking each other's way: given the right circumstances where two really super-sensitive souls encounter each other the whole embarrassing fandango can continue almost indefinitely.
Vannier,” the chauffeur said behind my back, in the drawled, over-polite voice of deliberate insolence.