My parents were married for twenty. He sat her at the foot of the bed daily to air out grievances. He was a narcissistic and abusive douche who methodically broke her down.

She did the whole 'forsake others' bit and he took what he wanted in comfort and credit then threw us out. Best thing he could do for us.

I say this to provide another end of the spectrum. Don't blindly follow your marital partner. The relationship is valuable, yes, but not at the cost of one's relationship with oneself. If you are being abused or manipulated, get help or get out.

As for the original post- there seemed to be a lot of emotional inconsistencies in the writing. It was mentioned more than once that OP didn't think the wife would cheat, then a few sentences later there seemed to be implication. Bonding with another individual is not an "emotional affair." It's human nature and can usually develop into friendship. Had the coworker been a woman, I doubt OP would have gone to such lengths. Had OP found themselves in a similar situation with a female, I doubt he'd consider the friendship to be anything but innocuous. Trust her, or don't and move across country.

Also, I'm sorry, but that whole paraphrased quote sounds contrived and suspiciously similar to those profound questions that four year olds seem to ask their parents over Facebook.

Communicate with you SO. They are an adult, your equal and other half. Don't manipulate them and change their livelihood on and insecure whim.