I think they might just be regurgitating with each other. That is called love or great friendship. :) I HAVE AN OLDER FEMALE AND A YOUNGER FEMALE THE OLDER ONE IS VERY MEAN TO THE YOUNG ONE THEY DO...
It is best to get it one of those hard stick-type foods as a treat, this should allow your parakeet to keep it's beak from growing too large (im not certain that they do this). If this does not...