Don't teach Dhamma to those who can't appreciate it or aren't interested
The Buddha not only stressed the importance of right speech but also the right time and occassion to say it:


  "So too, prince, such speech as the Tath›gata knows to be untrue, incorrect, and unbeneficial, and which is also unwelcome and disagreeable to others: such speech the Tath›gata does not utter. Such speech as the Tath›gata knows to be true and correct but unbeneficial, and which is also unwelcome and disagreeable to others: such speech the Tath›gata does not utter. Such speech as the Tath›gata knows to be true, correct, and beneficial, but which is unwelcome and disagreeable to others: the Tath›gata knows the time to use such speech.613 Such speech as the Tath›gata knows to be untrue, incorrect, and unbeneficial, but which is welcome and agreeable to others: such speech the Tath›gata does not utter. Such speech as the Tath›gata knows to be true and correct but unbeneficial, and which is welcome and agreeable to others: such speech the Tath›gata does not utter. Such speech as the Tath›gata knows to be true, correct, and beneficial, and which is welcome and agreeable to others: the Tath›gata knows the time to use such speech. Why is that? Because the Tath›gata has compassion for beings.” ~~ MN 58 ~~