Venting every feeling isn't mature. Learning to deal with uncomfortable and unpleasant feelings is an important aspect of maturity.
Did you ever have a conversation with someone who misunderstood everything you had to say? It's exhausting, and the ironic part is that the more you try and explain yourself, the more mixed up things become. Your best friend knows when you're kidding, venting, and tired. He or she knows you and therefore doesn't read into the things you say.
How many voices have escaped you until now, the venting furnace, the floorboards underfoot, the steady accusations of the clock numbering the minutes no one will mark. The terrible clarity this moment brings, the useless insight, the unbroken dark.
Scores of studies have shown that venting doesn't soothe anger; it fuels it.
Too quickly, venting can turn into dumping garbage on the people around us.
[It is easier] to quell emotion than to incur the consequences of venting it.
Lyrically, I personally lean towards venting.