He admits it's because he thought I'd be annoyed or suspicious and he didn't want to cause any problems between us.
So he does things he knows would upset you if he thinks you won't find out. Nice.
He says, because he's kicked up a bit of a fuss in the past over my male friends
So he's a hypocrite as well as selfish. One rule for you and one rule for him.
I remember your other thread. This is getting ridiculous now, he’s really done a number on you for you to be wondering if this is ok.
It doesn’t matter what it’s called. Emotional affair / inappropriate behaviour that really upsets your partner and makes them feel shit about themselves as well as being utterly hypocritical because he wouldn’t like it the other way around.
You’re asking about what to label it as, as if that makes a difference as to whether you have to put up with it.
He would rather do something he knows would hurt you and keep it secret, than not do something that would hurt you.