Attention, attention

Now what should I do when someone deliberately does something just to get my attention and admiration? Okay, specifically that person is trying to show off to me their precious treasure (e.g. luxury items, branded schools, great career, beautiful kids, expensive holiday trips, kids' good grades, etc). Of course, people like this kind are not my close friends (my girlfriends are nice people!). Sometimes it's just people I'm forced to interact with. 

I normally roll my eyes and pretend not to notice. I'm just wondering now if I should just give them what they are craving for (my Waahs and Wows) so that they are satisfied and we can just move on? 

People who have the constant need to show off... Are they insecure people? Or are they just arrogant, inconsiderate and proud? 

Whatever happened to humility? And maturity? -____-