Didn't read sidebar: My bad.

Mission: Wife emotionally cheating with my daughter's beefcake 4th grade teacher (does not appear that he is aware or overtly involved in anyway), not sure how to handle it.
Stats: 5'9" 160 lbs, something around 13 and 15% bodyfat (no idea, haven't had my body fat checked since high school), 215 bench (i know, i know), 315 squat, 335 deadlift and last week got 15 miles running in, typically i'm between 5 and 10 for the week. I have not read any of the books recommended in the sidebar other than the Bible and only slightly familiar with RP.
Finances: No debt other than mortgage, make around 100k per year, no significant investments other than a few 401k's.
Spiritual: Read everyday, mostly a devotional and daily reading plan stuff and pray a few times a day about random stuff, nothing intentional or scheduled. No memory verses in years. No evangelism. No sharing of faith unless the topic comes up. To contrast my wife is an uber Christian so this is certainly one of the ways she is unsatisfied.

Looking for encouragement, advice and similar stories to help figure this thing out.

Background is we met my 4th grade daughter's teacher at school orientation and knew instantly to tease my wife about how good looking this guy was. He was really nice and friendly with my kids. Not sure who was smiling wider though, my wife or my daughter (the 4th grader and oldest of the bunch). Didn't bother me at the time all that much but of course one always compares and contrasts. I teased my wife a little about the hunky 4th grade teacher here and there over the last few months and she played it cool and acknowledged he was very attractive.

Mostly we'd comment about my daughter having a little crush on him but the truth is she has been much more mature about it than my wife.

We attend church weekly in a non-denominational church, have four children and have been married for 12 years. My wife is the spiritual leader of the family, which I acknowledge is part of the problem. She is very charismatic and believes herself to be something of a prophetess, having gifts of prophecy and prays at least an hour but often up to two hours a day. She has a lot of "spiritual" dreams and often spends time interpreting them with her mom and some other women at our Church.

So about a week ago she revealed to me that she had been having dreams about the teacher. I pressed a little and expressed concern that she's been dreaming about this hunky school teacher. After some conversation she reveals she's been lusting after him pretty much since we met him, fantasizing about him, etc. This initial conversation ends with the understanding that she hasn't done anything or engaged him other than about our daughter on this parent/teacher communication app online that started up last year during covid. It's pretty much like discord.

The next day I press her about the online app and she says it was no big deal, she refuses to show me the messages, I find the messages and she's been flirting with him on it. He's been friendly and responsive but I wouldn't say he was also flirting but definitely too familiar for a parent teacher relationship. Sending her pictures of our daughters work, cutesy emojis, complimenting my wife on her parenting, stuff like that. The stuff she said was pretty PG but obviously flirtatious, calling him "mister" and "hey you".

I also see that she messaged him that morning, the morning after everything was first disclosed to me. Nothing super exciting but asking him a question about a dream my daughter had (however much more likely a dream that she herself had). Nothing to do with school at all.

Some reasons she's given about talking/lusting/fantasizing are boredom, wanting something exciting, mad at me for various short comings like physical fitness, spiritual leadership, following through with things I say I'm going to do, etc. Also she's said that she's not sure but maybe looking for validation from another man that isn't her husband because I have to tell her she's beautiful, etc.

She's a beautiful woman but I'm no bullfrog. This guy is certainly in better shape, he's a total beefcake but she's been lying a lot through this so I just don't know what to do. I shouldn't have to explain though I did over the past few days that she's a mother of four, a devote Christian, women's leader in the Church and married to an adoring husband. I'm certainly not perfect but I've never mistreated her or shown anything but love to her over the years. I absolutely need to step up my spiritual game in the house and I started upping my weight training prior to all of this but am in pretty good physical shape already. I powerlift weekly and run quite a bit, a lot more the last few weeks.

I have no one I can talk to about this because they all know my wife and would feel betrayed if I asked for advice or help on this.

Update (21 hours after post submission)

By no means is this over or resolved but we made a lot of progress last night.
I want to thank those of you who took time to hear me out and offer advice, it really helped. I'm the problem and had allowed myself to get lazy, complacent and comfortable. She married a HVM, not whatever I've been turning into. I have a lot of work to do but last night was a great step in the right direction.