I see going through a phone/gadget on a par with rifling through a handbag diary/underwear drawer, out of order and I would be pissed off if someone did that to me.
I suppose the question is not to drip feed or ask for judgement but to ask what people think about if it is ever reasonable to look at your OH's gadgets ? I'm not looking for an excuse or reason to do so, I've chosen not to snoop but I wonder if I'm being a bit naive or out of touch. My situation doesn't currently warrant a snoop but I'm not naive enough to be one of those 'he'd never cheat' brigade but at what point do you think, fuck it, I'm going in ?