A world to define ones 'gender' not sex.
Boys do not need to have a penis, and
boys do not always play sports either.
Boys can be feminine, boys can be masculine. If they call themselves a boy, they're a boy, no questions asked.
"Hey, did you hear about Sarah? She won that super cool trophy yesterday!"
"Oh, you mean Ethan?
Ye he totally deserved it."
"He? She's a she?"
"No,
respect his pronouns, he's a boy. What's in his
pants doesn't matter."