discreet

adjective2

1. •
   Respectful of privacy or secrecy; exercising caution in order to avoid causing embarrassment; quiet; diplomatic.

   • With a discreet gesture, she reminded him to mind his manners.
   • John just doesn't understand that laughing at Mary all day is not very discreet.
2. •
   Not drawing attention, anger or challenge; inconspicuous.