Privacy question between boyfriend and girlfriend.

This is always something I’ve been curious about in relationships, and I’ll spell it out.

Obviously trust is a huge part of all relationships. Both parties in the relationship must trust the other in order for it to work out in the short and long term.

However, what happens when one person breaks that trust, and in doing so, finds out the other has done the same?

Here’s an example:

The boyfriend or girlfriend goes through the other’s phone to read their text messages and/or phone calls. They find out that their s/o has been texting with someone else or mentioning things to others that don’t seem appropriate for someone in a relationship. Here’s an example of what I’m talking about.

I had a girlfriend once who went through my texts. I had a conversation in there with a guy friend of mine. He had gone to a party with a girl friend of mine who I had used to date, but my ex had brought her new boyfriend with her. I didn’t go to the party, but I had asked my guy friend (in the text) how the new boyfriend was. I wouldn’t say I was asking cuz I was jealous but I was just curious how I stacked up next to him, you know how guys can be. Anyways, she saw this and questioned me about why I cared so much about the new boyfriend of my ex.

Is it worse that she went through my phone, or that she actually saw something worth commenting on? Did she find enough to validate going through my phone? I personally don’t think so because I don’t think I did anything wrong and no bad intentions either.

Obviously there are more extreme examples, ones in which the people actually get caught CHEATING by others looking through texts, emails etc. Anyways, I’m just looking for the fluther’s communities thoughts on everything I’ve said. Thanks jellies.