Just general points:
I read a good psychology article a few months ago in a science mag - said that the more people try to behave like model citizens, the more they eventually rebel. So the more we constrain people not to talk to other people, not to confide in them, not to be friends with them, the more likely it becomes that they will eventually do something really stupid.
I have (quick count-up) nine good male friends. I'm in contact with each of them each week, some every day. I have about the same number of good female friends, on the same principle. If I told my dh every time I was in contact with each friend and what we talked about each time, he'd have no time to do anything other than listen to my account.
A good relationship is about trust and respect. He trusts and respects me. I trust and respect him. I don't deliberately hide anything from him, but if a friend comes to me for confidential advice, I don't break that confidence.
I don't slag off my dh to other people, and I'm always very aware of the need to cheer on the relationships that others have with their own other halves and never ever knowingly get in the way of that.
So...an EA is not to do with sharing every single friend's confidences with your OH whether a friend wishes that or not. Nor is it something avoided by imprisoning the emotions and behaviour of your partner in a way that stifles their ordinary everyday friendships. It's when you fancy someone and pursue that lust, wanting to be with them as your sexual partner, and undermining your own relationship and any relationship they are in. secretly hiding the real nature of the relationship from your OH. Well, that's my understanding of it.