This is from my archives, and pretty well sums up Robx's approach. It was his advice to another poster, but 90%+ of it applies:
Sit her down and have a discussion with her. No need to be mad, angry, a$$hole, prick on anything, keep it calm, light but straight forward, direct to the point, etc. Don't make it last more than a few minutes.
You tell her trust is based on actions that are consistent.
You don't trust her because she hasn't been consistent.
You don't trust her because she's been lying to you, in fact you tell her that is what you trust her to continue doing, because she has been lying to your consistently - that's what you can trust.
For you to be able to trust her, she has to build trust. Sure you can trust her blindly and have faith and all that good stuff but honestly how well has that worked up to this point?
Don't ask for for full disclosure.
Do the opposite.
Tell her this:
"... I don't want your cell phone records, I don't want to look at your cell phone text msg's and call history, I don't want your email or fb password, I don't want your voicemail pw. If I have to monitor you 24/7 to force you to be consistent, that won't work for me because that's not what I want or need.
I wanted you to be trustworthy but I don't need you to be anything, truth be told, I'll be just fine without you, I see that now.
From now on I'm moving in this direction, if you want to come along, go ahead, I won't control you and tell you that can or can't come but I can't wait for you anymore and you already know that if you're with the OM, you aren't with me, I'm not settling for anything less than that.
If you really want to be with the OM, I really can't say or do anything to stop that and you should be with him if you're willing to lie so much to me, if you can't be true to me that means he's more important to you than I am and you know what... I'm ok with that because I'm more important to me and that's all that matters - I see that now.
If you wanted to be with me, you knew that you had alot of trust to rebuild and that's only through consistent action and I'm through with pressuring you to be my wife, I don't want to be with someone who doesn't want to be with me and that's pretty much what it looks like to me so let's stop playing games: you go and be with the OM, I'm ok with that, in fact I'm better than OK, I'm awesome because I'm finally being honest with myself about all of this and that includes being honest about who you are and where you are right now. I know what I'm worth and I've been settling for less for too long.
I can't wait for you anymore, I've spent enough time waiting for you to do the right thing and I know that doesn't work because I would probably have to wait forever and still not get what I wanted. So you can do what you want, be with the OM, I hope he makes you happy and I'm going to start wanting something better for me."
No being mean, spiteful, vindictive, you let her go. No more discussions, arguments, no more talks about lies, no more sneaking around behind your back, she can do what she wants but you are letting her go to do what she wants to do but at the same time, you are now allowing yourself to be free of this crappy limbo place you've been living in for so long.
Bro, if she wants to be with you, she'll be with you, no amount of a$$ kissing, sneaking, snooping, being mean, angry, standing tall, etc. is going to change that.
You be the best gosh darn example of a MAN for you and for you only. If she wants this great MAN that you are in her life, she'll pursue you and do what it takes to be a part of that.
You need to respect yourself first, that's the first step and letting go of your wife her untrustworthy ways to establish that your self-respect, dignity and integrity are the most important things in your life is what you NEED and WANT to do. You know what you're worth, go out and get what you're worth and let go of the things that are worthy of you - starting feeling your personal value, know it, resonate with it, live it. You are worth better than what she is giving you right now, if you don't set that boundary, you'll allow her to do this to you forever and who could respect that?
Otherwise continue playing this game and you'll be playing this chase & pursue game, pushing & pulling for the rest of your life.
Time to get off the merry go round, this ride isn't that fun anymore.
"What is best for my kids is best for me" Link to quotes: https://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=2879712