Gossip is harmful, 

even if the person never learns of what we said.

When we gossip about others, we may tell ourselves that we’re not doing any real harm. The person will never hear about it. What are the chances? We can tell ourselves this. But even if that is so, harm is still done.

When we engage in gossip, we waste our time and energy. Even worse, we waste the time and energy of those who listen to the hearsay we’re spreading. If we want to say something about others, we should be speaking positively about them, not passing on gossip.

Gossip usually involves something unfavorable, even malicious. Unkind thoughts are negative and, therefore, plant negative seeds, thus creating more negative karma. To make things even worse, just as we view those who don’t tell the truth as untrustworthy, our gossiping will deem us unreliable in the eyes of those who do value the truth.

So honest people will avoid us. Eventually, only those who do not value integrity will spend time with us.