I wouldnt care if my husband went through any of my stuff I have nothing to hide. We both have each others passwords to everything mainly because we only use 1 each for all our stuff I dont look he doesnt look that I know of. If he changed his password I might be curious and ask him why if that was done and his behaviors changed I may be a bit worried but something I was told in my first adult relationship is you cant stop someone from cheating they will find a way so best not worry yourself.
I have never been cheated on and I know if my husband cheated on me he would be a fool. The quality of women around that I have met and seen is crap anyway so he would be losing a good thing. He knows he has it good as all his last relationships have been what I have seen as the typical selfish, my way or the highway lazy women that we come across good luck to him to find someone that will treat him as good as I do. So I dont worry about it and just live life.