Welcome to Marriage Builders, gr8. Sorry you have to be here.
Your H appears to be in an Emotional Affair. You will need to start doing some heavy-duty snooping in order to get all the info about this A. For now, be as pleasant to him as you can be. Don't talk to him about the OW or let on that you are concerned about his faithfulness either way. You don't want to put him on notice that you are suspicious. If you do, he'll take his A further underground and it will be more difficult to get the info you'll need.
Here's how to get started:
1. Get a keylogger. Go online to
www.spectorpro.com and order the download. It takes just a few minutes to buy, and is easy to install. It runs in stealth mode, so he won't be able to detect it on the computer.
2. Get a VAR (voice-activated recorder). After you get it let us know and we'll help you figure out a place to hide it in his car. Most waywards need conversation with their AP (affair partner) and he more than likely can only talk to her when he's alone in his car. Don't get the cheap one - the reception is poor. Plan to spend around $75-100 for this.
3. Have you snooped in his car for cards, notes, email copies? Do so.
4. Can you get into his FB account without his knowledge? Go to the OW's page and copy all of her friends. You will need this info later.
5. Telling you he's been unhappy for two years is called 'rewriting marital history.' He's doing this in order to justify this A. Don't buy any of it. He's lying.
6. Read the articles on this site. There are tools here that will help you kill this A when you use them correctly. We'll help you, too.
You've come to the right place, gr8.