It's About Time

Apparently, the only time the Teenage Mutant Ninja Turtles conceal their modesty is when they emerge from the shower:

"What are you guys talking about?" 
"TCRI." 
"Oh, yeah?"
 "It's about time that you came out of the shower Raphael!  There had better be some hot water left!"

 "Don't worry about that big boy!" "Hey!"

Notes:
the past subjunctive is used in Ya era hora que salieras de la ducha because it is a clause that expresses a command or hope for a different subject.
Más te vale is a an expression such as There had better be... or God help you if there's not... etc.
Grandulón is a Latin American version of gradullón, said to a child who is big for his or her age.