Think pink and blue cupcakes are passé? Eric and Aly Nelson, of Minneapolis, took their “gender reveal party” in a different direction. They learned the sex of their forthcoming baby by way of the cheese in a Juicy Lucy.

It’s a tradition for the family that Eric started two years ago. A fan of the Minneapolis-born cheese-stuffed burger, he and his wife were unsure how they wanted to find out the chromosomal makeup of their child.

“Lots of our friends are having big baby gender reveal parties,” said Eric, who was trying to think of his own version.

Aly was less interested, and she shot down a few of his ideas. But on their way to a doctor’s appointment, Eric was still coming up with creative ways to find out the baby’s sex.

He was also thinking about lunch.

“I look for any excuse to get a burger,” he said. “Why don’t we go to the Nook and have it revealed by cheeseburger?”

At the appointment, the doctor wrote down the sex of the baby without them seeing, and placed it in an envelope. At the Nook in St. Paul afterward, the Nelsons handed the envelope to their server and explained that they would have two Juicy Lucys; the filling, however, would be determined by what was in the envelope. Yellow cheddar for XX, white pepper jack for XY.

Turned out, they were having a pepper jack, whom they fittingly named Jack. He’s now 2.

With Aly again pregnant, the couple decided to get their baby news from the Nook again last month. This time, they got the yellow cheese. No decision yet on whether they’ll name her Cheddar.

Uncannily, they had the same server both times.

“That was literally the first time in my serving career that this happened,” said Peter Hankee, who has been a server at the Nook for 10 years. “I was just shocked. It was a cool way to do things.”

Peeking into the envelope was a big responsibility, he said. “I was actually a little nervous.”

The second time around, though, he found himself excited for the Nelsons, because “I wanted it to be a girl.”

Thinking of following in their Juicy Lucy footsteps? Eric has some tips for prospective parents.

First, choose two cheeses with different colors. Eric’s favorite Nook burger is stuffed with pepper jack and his wife’s is filled with queso blanco. Two white cheeses wouldn’t work for this project.

Second — and this is really important for any Juicy Lucy eater — don’t bite into the burger when it’s hot, no matter how impatient you are to find out what’s inside. Lest you want a scorched mouth. The Nelsons cut into the burger and let the cheese ooze out the middle to learn of the secret within.

And lastly, don’t mess up a good idea. “Hopefully nobody’s going to turn their cheese blue or pink,” Nelson said. “That would totally ruin it.”