Lying, Purple Cheeks, Oh, My!

Suppose that every time you lied, your cheeks would turn bright purple.  It's hard to imagine, isn't it?
  I have just thought about a few things that might happen. For instance: No thief would get away with anything. That would be better, because, as soon as someone came in for questioning, the police would find out if he or she was lying, without even getting out the lie-detector. So, in that case, it would be a good thing.  
  But if you were trying to make a friend feel good, and she was asking how her new sweater looked on her, and it wasn't that great looking, and you were trying to say something nice about it, then bright purple, lying cheeks are not helpful.
  Also, if you were trying to keep a surprise, and people would be disapointed in you, if, say, you gave away the news about someone's surprise party. Yeesh! Not a good situation to be in... But the good news about that is, that your friends and family would understand, if they had gone through a similar type of dilemma.
   Or, how about if you lost or broke something your friend loaned you, and they asked you to please give it back, your friend would know right off the bat, that you no longer had it. The good news is your friend would already know by your flaming purple cheeks. Telling your poor friend would be somewhat easier, since it is often hard to tell someone about bad news.
   In conclusion, most things about having bright purple cheeks when you lied, would be difficult.