Wife has a work husband,enotiinal cheating confirmed, how to handle?

39M, been married to my wife 31F for 6 years, we have a 1.5 yr old son, blessed with all 4 grandparents, and large support group of friends and family.

Her coworker, 48Mish, has tried before to get with another coworker who was married to a POS cheater, and she denied him, she transferred to another hospital, unrelated. He’s in a shit marriage.

Us men, we know when a guy is trying… and doing too much. He lent us his icebox when our fridge broke, came solo to our son’s 1st bday and served food. I’ve joked and seriously stated he likes my wife, she denies. I trust her, never had to check her phone or anything. I’m no saint, we’ve been together 12 years and I was club promoter/rat, but I’ve never cheated, and grew up and settled down with her.

With our son, I do all laundry, dishes, cleaning, project cleaning, baby proofing, tons of DIY work, and half the diapers, baths, and being a present father, I’ve always wanted a son, no skin off my back. No doubt I’m an amazing father and great husband, everyone in our circle tells her how lucky she is.

Even before marriage and this guy, intimacy was declining, she doesn’t like PDA, but a hug or a kiss after work or while cleaning wouldn’t hurt. I was her first, intimacy was rough, it would hurt her (not saying I’m huge) but we’d have to stop a lot for her pain. Only 2 times sex since he’s been born, but I’d just like a hug or a kiss or a cuddle when I’m busting my ass, something… I chalked it up to dealing with an infant and not sleeping in the same bed.

I’ve worked on everything she’s stated to me, to try and become more best friends, interested in each other’s passions, etc. but it’s hard I’m extrovert and most of what I say or do in public spaces annoy her, she’s somewhat sheltered.

I’ve never felt the need to check her phone. Yesterday, she orders DoorDash, asks me to get it because she is putting baby to sleep. As I get it, he texts “ok.” I open it, nothing before it. She told him to not text because I’ll have her phone. I open deleted texts, and there’s 2500 over the past 3 years. Nauseating cutesy back and forth to eat lunch and breakfast daily, “I didn’t get to say bye to you” “you looked cute in your dress” “I only tickled you sorry” disgustingly she’s send him photos of our son, updates on his sick days and whatnot, and he’d always send her stupid selfies and old cringe younger photos of himself.

2 essay texts, one in March and one last week, about how in love with my wife he is. He can’t stand not being around her etc etc. he’s cried about his marriage to her, she’s opened up to him about our marital issues. In her defense, she did shut both down with “lols” and whatnot. A lot of his texts did go unanswered. But she strings it along with the honeymoon type texts… and who knows what’s said in person during those lunches and breakfasts.

She claims he only tried to kiss her once and she deflected, but admits she has some feelings for him. I think that’s horrendous, since she always claims in our marriage she doesn’t feel the lovey stuff, but if she’s filling her emotional meter at work, there’s no need to at home fill it, so I’m left with nothing.

As a guy can’t help but assume they’ve hooked up. She denies, but here we are. I don’t want divorce because of our families and our amazing son, but what do I do???

tl;dr coworker is a constant homewrecker, wife is naive enough to catch some feeling and lied for years about it, physical stuff is not confirmed, but emotional cheating is confirmed by her.