None of the messages were flirty or sexual. But still. In my mind, it was a line crossed.
Mombear,
I can understand your feelings of betrayal. He's discussing something private and personal with another woman and, I would assume, you felt like he should be discussing that with you and not sharing with another woman. I think that's a very normal reaction on your part.
Are you the one that decided it was not an EA or did your MC have some input as well?
