Well you certainly have a problem whether it's physical or not yet. She may not be admitting to herself that this is an EA.
Questions:
1 Is he married?
2 Does she let you read her text message.
3 Is she deleting text before you can see them.
4 Does she have email, facebook, etc. If so does she share the passwords.
I speculate the answers to 2,3,4 are no, yes, and yes and no.
Anyway one thing that makes this tough is that an emotional affair requires separation from the other other guy meaning he or she would have to change jobs. It sounds like she's all happy about having this job so good luck with that.
Some bad news: My ex wife had an affair with her Boss at work years back. It was her second affair so I filed papers and we divorced. They are married now to each other and I am re married as well. I wonder sometimes if the fact they were both married when they started messing around causes problem.
What ever happens, it will not be easy no matter if it's only EA and ends or PA and continues, or you stay together, or you split up. Marriage is a big deal so there's a lot motive to stop this before it gets further out of hand.
Look at this link. It's pretty awesome.
The Love Bank
If you and her want to feel in love again it may help.