I don't see what's so weird about the growth spurt over the course of a week. His curse is no longer stifling his growth, so why not? Sure, the growing pains might be incredibly painful but...uh...have none of you been paying attention to his entire life for the past ten years?
Aaaaah. This idiot.
I like to think that the teacher intentionally started hitting on her to get Alejandro to behave. Now, every time he runs off is just another excuse to come see her again.