User blog comment:LastationLover5000/Fairy Tail 283 - In Which Nakama Is Spoken (Natsu vs. Sabertooth)/@comment-4728047-20120519164537

Minerva calling Dumbledouche "Father" may just have something to do with her all but archaic speech patterns, or her term of endearment for him like how practically everyone in Fairy Tail calls Makarov "Gramps"