Holding back with a smile — reluctance worn playfully; disclosure that makes you ask twice.
Old French coi (quiet, still), from Latin quietus (calm, at rest), from quiescere (to rest); reluctance worn with a stillness that invites a second look rather than closing the matter.
Holding back with a smile — reluctance worn playfully, disclosure withheld just long enough to make someone ask twice. Its own root was simply quiet, before it learned to flirt.