Padre
To most young children, their parents are Mommy and Daddy (allowing for plenty of variation, even for the English speaking world).
In the mid-summer of 1971, Michael & Jessica, along with Rachel and David, headed to England for Michael's sabattical at Imperial College. Before settling in London, the four of us took a three week vacation on the continent, travelling through France, Switzerland, and Italy.
I suppose it was to expose us to other languages that my parents taught us the Italian names for mother and father, that of Madre and Padre. Considering the extra connotaton of "Padre" as a Catholic priest, it certainly generated some surprised looks seeing two kids (ages 11 and 7) walking through, say, St. Mark's Square in Venice, calling "Padre, Padre!" in broad American accents.
Somehow, the appellations stuck, and our parents were "Madre" and "Padre" forever thereafter, including for our spouses (but not for the grandchildren).
For the purposes of this web site, however, I (David) elected to to call my dad "Michael" throughout the site, because I thought it would be less jarring for the reader, even though I never called or referred to him by his first name during his lifetime.