How would you address the priest in Hungarian? In English it would be 'Father Peter'.
My recollection is "tisztelendő úr", but I may be wrong. That was the polite address when I was a child growing up in Hungary. It vaguely means "reverend sir". I think "Péter atya" would also be acceptable, but a lot less formal. "Atya" is archaic for "father".
All my friends say Attya after the name, like "Gábor Attya", well in Budapest and Catholic Church I don't know how it is in other places and churches