She deletes the conversations, deletes dashcam footage, deletes Internet history, deletes all emails. All things she never used to do before starting talking with him. Plus the instant they became friends was the instant all of this started so it's not like its a gradually increasing friendship that eventually goes too far.
Sometimes as a new BS it can be really difficult to not only see the absolute absurdity of our situations (of course I know you see it), but also to see how bad it really is.
Many of us flounder for weeks and months at first with these things you describe happening all around us.
Remember: in a normal and healthy and honest relationship, deleted texts/emails/browser history are not a thing. Slightly tilted-away phones, phones set screen down, phone passwords changed, phones never left unattended or unlocked...these are not things that happen.
In a normal, healthy relationship, not only are phones casually left lying about and often lost somewhere in the house ("Honey, have you seen my phone??"), but partners generally know each other's passcodes and have full access to everything there ("Honey, can you send so-and-so a text saying we'll be there at eight? I can't, I'm driving.")
That's normal.
This means that when you finally do have your confrontation (and I hope you have it today, honestly), you can and should give yourself a little pep talk reminding yourself that you can be 100% certain that something inappropriate is happening here.
I KNOW how crazy-making it is to not know exactly *what* the hell is happening. Sucks that you can't get that. I'm sorry.
But you absolutely have all the evidence you need to confront and, as Bigger has advised, do something like this:
Consider this approach. Instead of asking if she’s having an affair then sit her down and tell her you are concerned about her relationship with this man. See what she says and respond accordingly. It’s just an innocent friendship…
OK so she would be fine with you seeing their correspondence. Invasion of privacy… Yes, but if you two intend to be life-partners there needs to be a deep trust that goes both ways. Right now, you need assurance, and the correspondence can give that assurance.
Expect her to throw the “you don’t trust me therefore there is no hope for us” card at you. Counter it with “if you trusted me you would share this info.”
Ask where they meet, how they meet, what they do.
Ask about the sexual harassment instances. What’s that about?
LISTEN to her. Don’t counter or dispute. For now you want her story.
Ask her if she is willing to go through Not Just Friends with you.
Remind her that the only thing keeping her in this relationship is her free will. If she wants out or thinks the OM offers greener pastures, then that’s OK. It’s not what you want but nor do you want to impede her happiness. Since you two aren’t married, no kids and so on it boils down to who takes what if you separate. You can stress its not what you want, but you would prefer that to learning she’s having an affair.
Again, as I mentioned, you really do have to plan for the fact that she's going to tell you that they're "just friends," you're crazy/jealous/etc., and that there is nothing going on. Go in expecting that. Still, ask those basic questions that Bigger suggests, make those statements, absorb everything she does and says.
Maybe I'm wrong. Maybe she'll break down in tears and tell you absolutely everything, beg for forgiveness, and swear to her favorite deity that it will never happen again. Doubt it, but it's possible.
My better guess is that, once you confront her and you've had whatever conversation you're going to have, she'll suddenly have a long walk to take, or a long bath with a locked bathroom door, or need to run to the store, or to work...you get the idea.
Watch her, listen to her, take it all in.
But beyond that--and this is important--you can and should already have a plan in place for what you're going to do after these things take place.
You can make that plan here with us if you like.
Sorry you're here and I know it's shitty and sort of scary, but after rereading your posts, I can see that you do have some basic plans forming. I personally think you have everything you need to confront today.