There are those who through their falsehood and gossip cause great harm to the relationships of others. This can be the case even with intimate friends. The first action of this man is to spread strife. The way that this man does this is through lies and slanderous falsehoods. He starts by lying to one friend of the other about the actions of their "so-called" friend. Those who will not listen to gossip will shut down this kind of ruiniation of another.
The slanderer is just as dangerous - but his falsehood and lies have a far more sinister goal in mind. He is not content to just spread strife and discord. Look at the proverb for today and not that the one filled with slander - does so not just to cause arguments - but also to separate a man from his friend. He has a target in view - and that target is a friendship of which he is very jealous. Why else would he desire to see this relationship destroyed.
Once someone can penetrate your mind with slanderous gossip - it is hard to remedy the situation. The desire is to serarate a man from his friend - so that the one who sabatoged this relationship can see it destroyed. That way he can have a better one - or at least keep the two former friends from making his relationships look weak and feeble. There are some who just are not happy unless they are making others miserable.
Be careful around such perverse, small-hearted people. They are filled with bitterness and hatred because they usually want what you have with a friend - but cannot get it because of their ungodly ways and how they are unable to maintain a relationship due to their own selfishness. Avoid these people like you would avoid the plague!