And you ESPECIALLY don't hide your cell phone from your partner when they have a history of being the victim of infidelity! That's just ABUSIVE beyond belief.
You see Sunny, you don't need to find an EA on the phone, your H is already doing a lot of damage... you HAVE the proof you need in his current behaviour.
Even if the phone is CLEAN this secretkeeping is NOT something I can imagine you can accept in a marriage...
Every time he takes that phone into the bathroom with him he condemns himself as a bad husband... PERIOD