Often if we honestly look at our motives behind having triangular conversations, with third parties rather than direct communication with the person; we find resolution is not our primary motive behind the communication. Instead we often talk to other people to win favor, to feel justified in our stance, or to make ourselves feel better.
The only problem with "venting, complaining, or gossiping" about one person to another person, is it does not lead to a resolution of the issue and almost always causes more discord among the two individuals. Much of the tension between certain women is based on a slight, a grudge or a misunderstanding that if talked about could most likely be resolved.
So if you have not been happy with the outcomes of issues you have had in the past with others. Next time try going directly to the source of the problem to look for resolve.
Be Impeccable With Your Word: Speak with integrity. Say only what you mean. Avoid using the word to speak against yourself or to gossip about others. - Miguel Ruiz