Jim Hoff and fiance Meg Moscato

Jim Hoff and his fiance, Meg Moscato, at their home in Downers Grove on Thursday, May 10, 2012. (Corey R. Minkanic/for the Tribune / May 9, 2012)

Every young couple thinks their wedding will be extraordinary.

But when Megan Moscato and James Hoff get married this summer, that's a sure bet.

The man who will marry Meg and Jim at a Roman Catholic nuptial Mass is Dominican priest Robert Botthof.

It's hardly a shock that a priest will officiate. Except this priest is also Jim's grandfather. Yes, his biological grandpa.

And that's what makes their wedding so special. In a religion that does not allow priests to wed and requires them to take a vow of celibacy, it is almost unheard of that priests have children — or grandchildren.

"We tell people Jim's grandpa is going to be marrying us. They know we're getting married in the Catholic Church and they go, 'Wait, how does that work?'"

It works this way: The Catholic Church permits widowed deacons to become priests.

While Botthof was principal of Oak Park-River Forest High School, Mary, his wife of 23 years, passed away. Two years later, he took early retirement from the high school and a few years after that, with his two children married, Botthof decided to study for the priesthood.

What makes his story even more unusual is that after he became a priest, Botthof served as principal and president of Oak Park's Fenwick High School (just a few blocks from Oak Park-River Forest), a job at the Catholic high school that at that time could only be held by a Dominican priest.

Botthof celebrated the 25th anniversary of his ordination this month.

Performing the marriage of the first of his five grandchildren is "very unique and special," he says. "To me it's very meaningful because I'm really committed to their happiness," says the proud grandfather, 83, who also participated in Jim's baptism.

"We're really excited to have him be a big part of our day," says Meg, 28. Jim, who is in public relations, also 28, calls it one more "cool thing" about their wedding.

Another cool thing is the wedding music. Meg is the band director of the fourth- to eighth-graders at Saratoga Elementary School in Morris, and her students will play at the church. It will probably be an arrangement of "What a Wonderful World," but Meg says that's still under discussion.

"They're so excited for this. Some are going out and getting special dresses. Some have changed their vacation too," she says.

The kids got in at the very start of the wedding plans when a guy in a Marco's Pizza jacket walked into band practice, March 18, 2011, carrying seven pizzas.

Suddenly, the fellow in the sunglasses and fake mustache was on one knee, holding a diamond and proposing to Meg.

Although they've been a couple since late 2006, Meg was stunned by the pizza gambit.

"I was overwhelmed and overjoyed," she says. "I was shaking I was so excited."

"I knew he was going to come up with something good. That's the way he is. … But the thing that is so weird, the way he proposed to me was like my dream proposal … in front of my students because they're so important to me. I thought it would be cool for them to be a part of it but I never told him that."