Q: 4000 texts + co-worker + 2 weeks = infidelity?

spying_on_your_spouse

While perusing the "relationships" subreddit of Reddit.com (not a terribly uplifting corner of the internet), I came across a post that made me pause.  Upon examining his phone records, the very upset author of the post had discovered that his wife had exchanged over 4000 text messages with a co-worker of hers over the past two weeks.  His immediate reaction was to start looking for a divorce lawyer. Srsly?

Later edits to the post reveal that he did eventually confront his wife, though much, much later.  The wife insisted that it was just a friendship, though the poster found this unconvincing, of course.  Last edit revealed he was trying to get a subpoena so that he could get the phone company to deliver transcripts to him.

I would normally laugh this off as an unnecessarily sad and dark example of traditional monogamy gone wrong, but the high volume of very supportive comments disturbed me.  Hundreds of people voiced their condolences and encouraged his decision making.

My world is very different from this, so I'm writing this post more as a survey so that I can wrap my brain around this situation.  If you're reading this and in a traditional, monogamous relationship, I would love some clarity and to field a few different opinions on this.  How much communication is "too much" if it's between your significant other and someone outside the relationship?  What number of texts or phone calls is inappropriate between your SO and a friend? A co-worker? An ex? A family member?  How long do you go before confronting him or her about it?  Do you snoop before your confront?  At what point does it become infidelity?

Let's talk.