If you want to keep things private you have to be careful and smart so that you don't have to lie.
If the circumstances allow you to tell the truth this is the best way to go. In this case you have to stand your ground and be honest. If nobody react than it's fine and you don't have to lie either. But it would be still your fault that you have been caught and then it is your duty to handle the consequences in a right way.
When the circumstances are very difficult you have to be more careful and lock your stuff.
There is never a need to lie if you can manage to keep things which nobody should know about private.
If you mention or show something to an other person he has kind of a right that you don't lie to him even if you don't wanted to. You don't have tell the whole thing though. You should just not lie!
