Is this a correct sentence in German? Why not "kein"?
With the given punctuation, 'Nein, keine Jungs' would be a better translation. With a changed punctuation, you could interpret it as saying 'no, no!' to a group of boys. That would be 'Nein, nein, Jungs!' in German.
I thought you could say Nein, Jungs neicht as well