Quoting ShellyBurger:" Does your SO/DH lock their phone like they are trying to hide something? Do they make a big deal if you ever go near their phone?"
My husband's phone is a corporate Blackberry.. he locks it ALL the time. I don't know the password, and I'd never ask for it.
Our phones and computers are our 'private' spaces, that get locked up, with passwords that only we know. I am absolutely comfortable with this and wouldn't change a thing, in fact I believe it's healthy and a trust exercise.
If something bothers me, I'd rather speak up than snoop..