The phrase mentioned above is one that is uttered in frustration - typically shared casually between two colleagues as the quintessential water cooler conversion.
While lamenting about one worker to another member is commonplace (not surprising since employees in every office have their respective cliques) it is an action that has negative impacts (which most people don't particularly think about) and is worth re-considering.
Here are some reasons why you might want to rethink grumbling to your co-worker about another worker.
1) Inter-office venting might come across as gossip
The predicament associated with airing your grievance about a certain individual to someone else at work is the fact that it can be misconstrued as "gossip", or worse, slander.
The best way to go about tackling such a sticky situation is to confide in someone outside of the company - that way there's no conflict of interest, and the likelihood of rumours starting is eliminated.
2) You're sowing potential seeds of discord
As a result of your words, the person you’re complaining to ends up developing a negative perception of the worker who has offended you. They could take things a step further by claiming ownership of your grievance, and start to treat this other colleague with disrespect (as a sign of solidarity to you). Such a situation could create an emotionally charged environment that disrupts the overall harmony and dynamics of the team.
3) The gradual erosion of trust
Trust is a vital component to the success of any relationship (personal or professional).
The propensity that this type of complaining has to corrode the relationship and trust between all parties involved is very high. The person you're complaining to, for instance, might become weary of you because they suspect that this is how you talk about them behind their back.
4) Robbing the offender of a learning opportunity
By not taking your grievance directly to the person who has offended you, you cheat this individual out of a learning experience; they might not be aware of their actions or know any better.
Your words (if delivered in the spirit of partnership) could serve as much needed feedback which could help with their reorientation.
As you can see, there is no merit to complaining about your co-worker to another co-worker; it's counterproductive and can be the catalyst for a firestorm and disharmony. So be encouraged to talk things over face-to-face, you just might be pleasantly surprised.