Spanish

Me and my brother always talk Spanish when we don't wish for anyone in the room to know what we are saying.  It infuriates my other brother because he says this is America so if I want to speak Spanish I should go down to mexico and speak it there.  Randomly I will also talk Spanish to my dad and he will counter that with some German he learned in his youth.  This is maddening to me because whenever I ask him to teach me some he refuses and yet when I make him made with Spanish I offer to teach him some but he ultimately refuses that to.