Do people who have nothing to hide really hide nothing?

This question is in response to my last question. I found out that my husband was texting a female friend of his that he's known years before meeting me. They never dated but he told he that he found he attractive but he's married now. He got mad at me for snooping through his phone. One of the people who responded told me that he should have came right out and told me he was was texting this girl. That immediately sparked another question. If you are texting someone of the opposite sex even though you are in a relationship would you just come out and tell your partner? I mean really, did I expect my husband to tell me he was texting this girl just to keep everything above board. The old saying is that what you don't know won't hurt you but eventually what's done in the dark does come to light. Is it wrong to expect your mate to tell you who they are texting and what they are texting about? I don't think I'm to that point in my life where I tell him everyone I text so why would I expect him to tell me who he was texting and what they said?