Is it odd that my friend who is 19 years old hangs out with 14/15 year olds?
The Lord Humungus.
Yes Unless he has some specific reason for doing this, such as an odd hobby, it means he is emotionally stunted.
There is nothing wrong with hanging out with people of different ages. It is also important for your friend to socialise with people their own age. if they are happy then, i guess it wont hurt anyone. :)
I'm guessing you are ''my friend''