Hurt --
But, you see, he DIDN'T actually think he could get away with it; he knew it wouldn't work. He's finally realized what he's really known inside himself all along; that if he didn't pull the plug firmly and definitively, OW could very well be back in your neighborhood in a matter of days. He just didn't know how to get out of it without ruining his chances with either one or both of you. While he's been somewhat less than unequivocal in this latest email, at least she's gotten the message.
I've always felt that H was being much too gentle with her, much too conscious of his "cake-eater" status, much too concerned with preserving his relationship with her over and above his marriage with you. Read why and HOW he tells her not to come: "My wife knows everything about you coming. Now I think it is better you don't come. Things are getting crazy again and you know what, I deserve it. I really don't want to make your life miserable. I am sorry." Full of misplaced contrition and equivocation. He's sorry about the wrong things.
It doesn't look like this thing is going to happen; I think she's understands the situation, so the problems of deceiving you or spending daytime with her and nighttime with you are non-issues, or so it would appear. The bigger concern is what is he going to do about you and your marriage.
OW has "spilled the beans" with the email game. She's right: gossip wouldn't have alerted you since it was nonexistent and she knew it. Fortunately, you've known all along what the two of them were thinking and planning, but only because you had that secret access. Maybe it's time that this all comes out, since you don't want to continue snooping for much longer, if at all. As you've found, it's not the most pleasant way to live, especially with one's marriage partner.
"Will he ever change?" -- Maybe now's a good time to find out. Maybe you should place it all out there on the table and see what he does with it.
"Do I want this kind of life?" -- Of course not. He can change but only if he wants to. He could do the right thing here and fully recommit himself to you and to your relationship. He's got to be "tired of running" too.
Bottom line: he doesn't want her here and he's told her and she's heard him. I think you're at least 20 paces ahead of where you were before. The rest of the distance is really up to him. Please let us know what you've decided and how this is going. We're with you...
Ammon