Can't call him father, so "This is my [dad, daddy, daddyo, papa, pops, pappy, sire, beginner, don, begetter, male parent]

Juan Viejo2

FF -
Likewise with my dad. "My Old Man" would have gotten me a smack on the ear in a blink of an eye. Same with calling him by his first name.
I even got the evil eye one time when I introduced him by his first name, rather than "my father, Mr. Viejo."
JV
FatFreek 2005

And on a more sobering note, did early JW's ever use the term Father for their leader?
In searching the early Zion's Watch Tower, from 1879 through 1916, I found it interesting that Russell refers to William Miller (Millerite founder) several times. Fact is, he referred to him as "Father Miller" no less than 4 times in early ZWTs. You may remember him as the originator of the 1844 debacle. Check outthis link.
Len