Infidelity Support Group
Any relationship in which one partner engages willfully in sexual relations with another outside of the partnership is considered to have experienced infidelity. This breach of trust is often traumatizing for the faithful partner as well as the relationship, and support is often needed to heal emotionally and to decide whether or not the relationship should continue after...
If she guards her phone a lot, there are other things you can do. There is the voice activated recorder you can place in her car. If you do get a hold of her phone, try common passwords she is likely to use, if you have any clues on those. If she uses a particular computer at home, install a key logger on it. If she does leave her phone accidentally open and available to you, do some research so you can install some phone spyware at a moments notice. At some point she's likely to slip.
But for me, the lack of transparency all by itself is enough to raise significant concerns. I would take the tact if she refuses to let you see her phone contents, you have to assume and act as if she is cheating, for you can make no other assumption. If she says she's not, then ask to see her phone to prove it. What is she hiding? There should be no "personal" business on the phone that you don't have a right to see short of her working for an intelligence agency of the government and the info on the phone is classified.
Maybe there is another explanation, but not likely. And if she had one, she'd tell you and show you. If you're married, then each others business becomes the others business. Otherwise, socially, there isn't much of a marriage going on.
However, from the way she's acting, it sounds more like she's NOT going to stop. Then what will you do? The worst case scenario would be for her to say she wants to leave you. So, you have to prepare yourself for a life without her. Please start making plans for what you will need to do. Be pro-active. Making plans for your future will help you feel better--at least you are doing SOMETHING, instead of just waiting for the bomb to be dropped. Figure out as much as possible in advance--money, property, your emotions and goals, and so on. This will make you stronger, and will give you time before you initiate a showdown. And please start right away, in case she beats you to the punch.
This is like the pioneers circling the wagons when they see the Indians coming over the hills. (feeble joke)
We are here for you.