I admire your commitment to teach more than one language! I think it absolutely is a benefit. Unfortunately, my father didn't speak Spanish around the house much when I was young  (he was busy being "American") and neither I nor my older brother ever picked up more than a little. My two younger brothers got to hear more Spanish after my dad went back to his "roots".  One brother is completely bilingual Spanish/English, and the other knows some Spanish and quite a bit of Japanese, as well as English.
