Keep working on the house and changing things up to suit your own tastes as though you intend to live there awhile AND to sorta start to get the place ready for sale just in case. Maybe paint a room or two neutral colors.
Cook up some break and bake cookies in the oven from time to time on any day you think wife might barge in. Nothing like the smell of fresh cookies to make the place smell all homey and trigger that longing spot that may yet remain in her heart (under the cold wayward shell). Leave a couple on a plate for her with a note maybe cordially asking her to please advise you of whatever she takes. Another day you'd might tell her "I'm painting the tea room and here's a color swatch, what does she thing" acting as if she's just out on a holiday and she'll be back. Bonus - you get cookies.
It may not be fair or ideal but her coming in and out could work for you too....let's her see you aren't sulking and keeping busy.
You might even go out on the net and find some document called something like "you should end your affair" or "20 reasons to stop your affair", print it, highlight a couple sections with some notes in the margins and then just leave it sitting around for her to snoop, find and read wondering what junk you are filling your mind with. It needs to be from another website so it doesn't lead her back here. She's probably much more likely to read it wondering what you are reading than if you hand her a document and try to teach her. Just leave it sitting on the kitchen table all marked up. You could even write in the margins some misinformation to really confuse them. For example, knowing OM will be advised of whatever she finds and reads, make some notes about him. Maybe you obscurely reference a background check you did on him that found some things from his past that you debated telling your wife about -
Something like: "Do I tell {wife] about OM?
Yes - She really needs to know what a degenerate lowlife he is and keep OM away from our son. If his boss finds out he could get fired and move away.
No- If he gets fired wife will just blame me and it'll make them closer. She's not ready to listen to you yet and will just dismiss whatever you say because she thinks she loves him. OM will lie his way out of it and you will just look like the bad guy. Save it for the divorce case. Talk to attorney about whether we should surprise them with it in depositions or write a formal letter/petition bringing it up now hoping to protect S9 to the largest extent possible.
He'll freak out. Guys like OM's always have deep secrets because only degenerates pursue married women. Plus, your wife KNOWS he's a lowlife liar so whatever she says she will be skeptical of. OM will have to go over everything he's ever done with her trying to figure out what you could possibly know.
I'm rambling. You probably won't bother with that convoluted an effort. I like tangents. They sometimes spur your own ideas whether you use this one or not.
The internet is 90% complaining and entitlement and I hate it because I deserve better!