To think that a password on phone isn't always a red flag? Or am I beings naive?

[Wishfulmakeupping]

Read various threads where the red flag has been phone behaviour- do you think this is always a cause for concern?
My OH has a password on his phone which I have questioned him about in the past- he says it's in case it's stolen or in case a friend tries to do a status in his fb or twitter. Aside from this I doubt very much he has been unfaithful we are together most of the time, he has never given me any reason to doubt him- and when women have tried it on with him he has been honest.
Should I be worried on the sole basis on phone behaviour he has password, and does take phone everywhere with him (he says for work reasons) and does have a tendency to hover if your on his phone but on the other hand I have no other reason to be suspicious of him. He has also told me the password he uses and says at any point I can check his phone - although he has said he'd be disappointed if I did as it would look like I didn't trust him.
Is there any need for me to be worried about this or not? Most people I know have password on phone but mumsnet threads are getting me worried!

I've had a password protected phone since my stepdad read my diary at age 14... Now it feels weird NOT to have one. My exDP didn't know the pass code, coz, well, I changed it to the works door code to help me remember the code, and changed it every 12 weeks (like works door code!!) and even if I had told him, he wouldn't have remembered it....!! Also, I occasionally sent texts bemoaning him to my friends. nothing too serious, or that he'd disagree with, but still not something I'd want him reading iykwim? Anyway, to me, on it's own, nope, no red flag. hth.

Some companies make you have a password if you have your work email linked to your phone, mine does and so did the last company I was with. Not sure if that's the reason in your partner's case?

Don't jump straight to 'unfaithful', it's more likely that he looks at porn or has nude pictures on it or just has dubious conversations with his mates.

And I take my phone everywhere with me so I can play games or MN in the loo

I don't have a password on my phone. Don't think that makes me stupid though, my logic is that if anything happens to me (ie I fall down the stairs) my DC need to be able to use the phone and call my Mum/999. If I set a password they might not be able to remember it.