There's venting and then there's VENTING. Sometimes we all need to just get things off our chest and have a sympathetic ear so that we can go on with our lives. Voicing feelings can make us reexamine those emotions from a different perspective. It can make us realize that the thoughts we're having don't sync up with reality or that we need to make a change.
However, I have found with some people that they get into a bad habit of constantly b!tching about their SO. Usually it's just a couple of issues that they may be unhappy with, but the rest of their relationship with their SO is pretty good. For these people it takes a wake up call for them to realize that they're poisoning their relationship. Constantly thinking about and recalling a bad event can become a self-feeding loop of negative energy and bring down the people in the relationship and anyone that they dump their feelings on. I have found myself on the receiving end of this and feel like I'm being used as their emotional tampon.:( Which is the impression that I'm getting from your post, Bluetree.
IMHO, part of learning to express our emotions is finding the time, place, manner and people with whom we unburden ourselves. Having a close friend who knows us well enough to know when we're venting and lending a sympathetic yet detached ear at those times is invaluable. They realize that the emotions we're expressing is out of anger, frustration, fear, sadness, loneliness, boredom, depression, grief or ??? and know that those are not how we feel the rest of the time. They'll let us unload, maybe give us an anecdote or two to let us know that we're not alone in having those moments, and know when to turn things around - at which time they can give us gentle reminders of the things we love about our SO.
I think as a friend listening to the situations it's important to stay detached otherwise it gets messy. Either it turns into a situations where the one listening says things that may come to bite them back later (Example: Yeah, I always thought he was a jerk but I didn't know how to tell you.) or it becomes a SO bashing event that leaves all involved feeling blacker.
ETA: It's better to be honest about how you feel about your friends unburdening on you, because if it's done in a manner that's bringing you down then it's not healthy for your friendship with them and the friendship that you hold with their SOs.
My $.02 anyhow.
