The righteous hate what is false, but the wicked make themselves a stench and bring shame on themselves. ~Proverbs 13:5
Don't put up with or participate in trash talk. Let the blabber mouth keep running, and he will run himself into a corner.
Speak truth - speak life.
Practice restraint and refuse to give an audience to anyone tearing people down. Stand in the way of trash talk by speaking life into the conversation.
You have the hope of Christ in your voice! Use it.