SunnyD may have a lot more to say here. She sounds in a similar situation to yours. Her husband is hiding his cell phone but he's not showing any other indications that he's in an EA or PA
A better question than the cell phone is what OTHER behaviours is he showing that are odd or make you uncomfortable.
Is he hiding his cell phone from you?
Does he password his computer?
Does he hang out on his PC at all hours of the night?
There are tons of websites with checklists like this.
I suggest you go beyond the phone to see what other stuff he's doing that makes you uncomfortable and put a list together.
