Do you have that best friend Thats not really your friend at

Do you have that best friend
Thats not really your friend at all
They always try to put you down
Saying "wouldn't you rather know the truth" 
When really they are so happy to see you hurt
They call you names and show off in front of their more 'popular friends'
they just use you to make themselves feel better
Do you have that best friend that's more like an enemy in disguise?