Yes. Yes they are! Demi has done EVERYTHING with Selena. They BOTH don't like Miley Cyrus either!
Miley, even requested a skype to Demi and Selena. They both accepted. So Demi and Selena started arguing over skype with Miley and Miley's friend.
see? Thick and thin!
I do think they are best friends, but they're definetly not as close as they used to be. Demi will always be there for Sel and vice versa. They've just grown apart.