If you cannot trust your own kids then you have done a lousy job at bringing them up!
I agree whole heartedly. If you are honest with your children about life, and have open lines of communication at all times, it will serve you well. The more you hide your own emotions and the facts about your own life, the less normal you will seem to them. I've never restricted them in what they dream of, and I've taught them good values and morals. When my youngest wanted a guitar really bad (he's seven) I explained to him how expensive a brand new guitar was and I showed him. I gave him several options, he could use my guitar or he could gather up the toys from his room and we'd put a value on them and he could trade them in at the Salvation Army and I would help him buy a used guitar. We talked about all his toys and he made all the decisions for himself. In the end, he gave away about $200 worth of toys to the Salvation Army and we went to a pawn shop and bought him a pretty nice electric guitar. He's played it religiously every day since and that was two years ago. He asked for guitar lessons from his grandparents for his birthday, and they asked him how his grades were and bought him the lessons because he was getting all A's. I treated my oldest the same way, and all of our neighbors talk about how polite and thoughtful my children are, and are always amazed at how they check in on time, and are respectful to us. They don't lie to other parents or teachers as well.
It is all in how you raise them. If you are open and honest with them, they will be open and honest with you. If you are realistic in your expectations about how your children should behave, and not punish them for not meeting your personal expectations if they are too high, that also goes a long way. Lots of positive enforcement and rewards for hard work done, is better than punishing for no work done at all.
It's how my parents raised me, and I was always honest with them even when I smoked pot, and drank... when I was 16 and thinking about having sex, my mom took me to get pills and would buy condoms. My parents couldn't pay for college, and talked to me about that long before my senior year, and together we made some decisions about how to get to college on my own and I made it through just fine. If you trust yourself, and how you raised your children, you can trust them. But also understand that kids are going to make mistakes, and you can be there for them even if you disapprove of their choices and can still help them turn it around before it's too late. Shaming them does nothing but draw them further into their shell.