It's happening with me ,

I lost my money on a gambling site so I know how I react when my parents are trying to reach me or talk to me .    When someone in my house hold trying to talk to me then I am trying to pretend them and one every minute I am touching my nose ,

So if your son or your any relative trying to pretend you and when you call him then if he will started touching his nose then he is hiding something from you . 

Biggest problem is parents who trying to put pressure on children so they are pretending to tell her or his problems to his parents.

So never scold your children for silly things.

Second ---

If your relatives or whom you trying to know can't talk you with your eyes to eyes contact than he or she is hiding something.

But you need to your relatives or children to ask them very lovely about his problems and promise to not scold them for this thing and giving a chance for not doing next time