Give the cheeky wretch all the space he needs.
He is not going to end this EA - he is going to make a choice, and given that he is moving out, that choice is unlikely to be you no matter what lines he's spinning you.
Don't sit passively awaiting his decision. HE disrespected YOU - & now it's HIM that needs space?
He can get to fuck with that audacity.
Don't be caught out or blindsided. You clearly don't know him as well as youthink you do, unfortunately.
Quietly cover your back, get everything in order, get advice, just in case. & don't tell him.
Don't kid yourself that he won't do the ultimate dirty on you. He is entirely capable of that and has already shown he's not trustworthy.
You may be able to get through all this, but not if you don't open your eyes and see this for what it truly is. Your husband taking the absolute piss. Deal with it on that basis - he is the one who's had the EA, he is the one who owes you a full and clear explanation.
He will be alone in a hotel - do you really, really think he is not going to meet up with this woman? & it's likely she already knows his current plans..as an add-on to him disloyally confiding in her about your lives together for a good while now, no doubt.
'Shocked', is he🙄
I really do hope it turns out she doesn't want him as a full-time partner. It would serve him right.
Good luck.