What do you hope to gain by "confronting" your wife? What more do you need to know about how she feels?
If you feel you need to know more, then just talk to her, but be real.
You don't have to feel guilty about looking at her phone. Just say you did it. If she passes judgment, who cares. It's done, you did it, so what. This is really hard on you, it's confusing, and you're trying to find your way through it. No apologies, no excuses needed.
Stop thinking in terms of "if I do X, then she'll do Y, then I'll do Z". The more you treat this as a chess game, the more you dig yourself into a hole of suffering.
Find your self respect and honor, and build it. If you don't see those qualities in yourself, your wife probably won't either.
You'll get through this.
Me: 50, MLC/WW 45 Young kids Nov 2015: BD1 Apr 2016: BD2 Jan 2017: W filed Feb 2017: D final