J class bathrooms
What is the policy regarding J class bathrooms? Is it ok for Y cabin passengers that are near the front to use the J class ones? Seems lately, I've noticed more and more Y cabin passengers using the front bathrooms sometimes causing a line up. Most of the time, I'm up front but when I am in the Y cabin, I would like to know if it is frowned upon to push back the curtain and use the front bathrooms opposed to walking to the back.
Cheers