Sorry that you're here, as others have said, CHEATERS LIE, she was leaving EARLY and staying LATE for work to be with OM, and I guarantee you they were having daily lunch together too (why not), we've seen it here thousands of times, workplace As are notorious for "lunch quickies" at a motel and/or make out sessions/BJs in the car. She was buying new clothes and lingerie to get compliments from him, well that means she went somewhere where she could show that to him, most likely a nearby motel.
Adults involved in As have sex when in close proximity, period. A man talking about sex positions with a woman attracted to him will not let that opportunity go to waste, you need to schedule that polygraph, don't tell her you did and just surprise her one day to go take it, you may get the "parking lot confession" but still go through with it, some of the questions should be (you only get to ask like 4 or 5 questions):
1) Have you ever had any type of sex with anyone since the time we started dating and while married ?
2) Have you ever been in love with someone else since we started dating and/or while married?
3) Have you ever made out or kissed another man in the lips, since we started dating and/or while married ?
4) Have you ever had any sexual contact and/or made out with OM (name him)?
5) Have you had more affairs besides the one with OM or ONS with anybody else since we started dating and/or while married ?
You have done some MAJOR rugsweeping, you should do ALL of the following WITHOUT WARNING if you're trying to R:
1) Make sure the A has ended (don't take your WW's word for it) and EXPOSE the A with ALL family and close friends, plus HR (he's a superior so he will get fired not your WW), your WW out of shame may decide to quit, another consequence of her A, remember she made the DECISION to CHEAT and kept CHEATING even after being confronted, nothing kills an A faster than FULL EXPOSURE, plus OM may confess more things to OBS, OBS will become an ally and another set of eyes to help ensure NC.
2) Contact an attorney to know your legal options and DEMAND she signs a postnup with an infidelity clause in your favor, if she cheats again, she gets no alimony and you get the lion's share of marital assets.
3) DEMAND she writes a detailed timeline of the A with full details and NC FOREVER with OM (she needs to send a letter approved by you with no sweet goodbyes).
4) DEMAND she takes a polygraph, in order to forgive you need to know what you're forgiving, you're still being TT'd.
5) Have her read "Not Just Friends" by Shirley Glass, you can download it today and is a short read.
6) She needs to go to IC to find out her "whys", why did she make the DECISION to have an A, remember you own 50% of marital problems but she owns 100% of the A, you're in the same M and didn't cheat.
Rule of thumb here in SI and other infidelity forums is that if they are in close contact there's a great chance the A never stopped or will resume in the future, OM knows your WW is attracted to him, what's more important to you, your WW's job or your M ? she can find another job but if you find yourself unable to forgive her because of a relapse or if she gets deeper in the fog, you or her may decide to D and break your family.
Keep posting frequently, this is a critical moment in your M and you want to have the collective wisdom of SI at your disposal with thousands of cases like yours, every case is different but cheaters follow a typical script but her workplace A is very common.
[This message edited by Buster123 at 10:38 AM, October 21st (Sunday)]