Is it okay to look at or through your partner's phone, whether that be out of suspicion (on purpose, you snooping) or coincidence (just happen to come across it or it appeared in front of you)?

Generally, I see a lot of people saying that it's BAD to be "snooping" around on your partner's phone or personal device. But, despite the "snooping," there have been many times where that is actually how a lot of people find out how shitty their partner is.

My general opinion on it is that everyone should have their personal privacy, including your partner. To me, it all comes down to respect for your partner's privacy. Maybe it's not just your partner's privacy, but maybe their friend's privacy. Your partner's friends probably would not want you to know their personal issues that they would have not told you to begin with. This isn't limited to friends, it can be to clients or whoever.

On the other hand, if you feel like your partner is hiding something, I feel like you cannot really validate anything unless you surf through the phone or other personal devices? I mean you can ask, but you can't really know for sure. What if there are alot of inconsistencies and weird stuff that comes up that gives you a good reason to think that something fishy is up? Probably by that time you have enough evidence that your partner is cheating or doing something out of boundary? Keep in mind that alot of people has found out about how shitty their partner is when looking through their phone or personal devices.

So, what draws the line when it's good or bad? (Whether it be that you are purposely "snooping" around with an intention in mind to find something specific, or you happen to come across something or something happens to pop up on you.)