They always lie about their relationships with their spouses (saying it's much worse than it really is... it's gets them sympathy, attention, control of the person they want --like a drug. Think about it, affairs aren't built on love, they are built on feelings of mutual sorrow, neediness and wanting to help the other person... add in the excitement of doing something "wrong" and lust... pretty powerful).
And they lie about everything else in an affair as well. Affairs are built on lies. That's why most of them eventually dissolve.
My guess is OW's husband only knows very little if anything. Right now, if it's presented as anything to him it's only an EA with his wife trying to help some poor guy struggling with a "bad" marriage and possible divorce. If he knew it was a PA my guess it he'd be much more angry. Maybe even threatening your husband. Most men don't like the idea of their wives having sex with other guys and wouldn't just accept it because they want their wives happy.
There is no arriving, ever. It is all a continual becoming.