GRASS LAKE, MI - People occasionally stop and stare at them when they're walking through the mall. At restaurants, servers routinely mix up who ordered what.

One set of identical twins isn't uncommon. But two sets of identical twins - particularly identical twins who are engaged to identical twins - draws more of a response.

"There is a woman at our church who was like, 'You guys just need to marry brothers and get a duplex,'" Krissie Bevier said. "And we were just like, 'Oh, OK, that's a funny story.' But it just became our reality."

Krissie and her identical twin Kassie are marrying Zack and Nicholas Lewan at Eyry of the Eagle Farm Wedding and Reception Center in Grass Lake on Aug. 3 and 4.

Kassie and Nick - the first couple to meet - are tying the knot on Saturday, while Krissie and Zack are getting married on Friday.

All four will stand in each other's wedding during the two-day celebration.

It all started in psychology class at Grand Valley State University - from which all four graduated. The girls grew up in Michigan Center, while the guys are from White Lake.

"Psychology loves twin studies," Kassie said. "So the professor was like, 'Are there any twins in the class? We're going to talk about twins.' And we both raise our hands."

Nick was sitting right in front of Kassie in the class. When the professor mentioned how many sets of twins were in the class, he turned around.

"I was looking around and I looked behind and I was like, 'Oh. I'm in trouble now,'" Nick said.

A few held-open doors and an exchange of phone numbers later, the pair started chatting. Kassie invited him to church one Sunday morning. To her surprise, he agreed. They both brought their twins along.

"We're standing there in the church getting ready to sing and they just start belting it out," Kassie said. "They were actually singing. My sister and I looked at each other like, 'Who are these guys?'"

A month later, Krissie agreed to go out with Zack. With each set of siblings having tight relationships with each other, there's a mutual understanding between the couples.

"The bond that they have, we have," Nick said.

While they don't go everywhere together, Kassie said about 90 percent of their dates turn into double dates.

The couples are moving in together into a two-bedroom apartment in Fenton, as the Beviers finish their doctorates in physical therapy at the University of Michigan.

Nick is getting his master's degree in mental health counseling from Oakland University and Zack does vegetation management in the forestry department for DTE Energy.

Mutual engagements, honeymoons

Zack and Nick didn't plan to propose at the same time. Eventually, they agreed they would pop the question on a family trip to the Henry Ford Museum in February 2017.

The two sets of twins and two sets of parents walked around for nearly two hours before the Lewans found the perfect place for the surprise. Their mother had given them smaller boxes to hold the rings, making them less conspicuous in their pockets.

Sitting in a century-old vehicle for the picture, the Lewans knew the timing was finally right. After some persuasion, they convinced their girlfriends to close their eyes.

Nearly 18 months later, the couples are nearly ready to tie the knot. They didn't want to share a wedding - as "being a twin, you never get anything on your own," Krissie said. But knowing they had a similar guest list, they decided to have the weddings together, but each on their own day.

Compromises like this are pretty common when you're a twin, Kassie said.

As a wedding gift, a relative gave the couples their own stay at a family beach house in Florida. The couples will go four days apart from each other - but meet in the middle for a few days at Disney World.

Meanwhile, the Aug. 3 and 4 dates for the weddings have some meaning to them. The Beviers' grandparents were married July 31 and have been together for more than 55 years, while their parents married Aug. 5 and have been together more than 30 years.

The twins' wedding purposefully falls between the two.

The couples click so well because they were brought up with the same type of family values, they say.

"I'm just really thankful that we met two girls - not just because they're twins, but they grew up the same as we did," Zack said.

Life with a carbon copy

The pair of 24-year-old duos say they hope to always live within walking distance of each other. They've always lived with their twin. The first time Kassie and Krissie didn't share a room together was weird, they said.

"For that three months where we had our own separate bedroom, we probably spent like two months with a mattress on the other person's floor," Krissie said. "It was just too weird to sleep by ourselves."

Now, all four of them hang out often. They call themselves "The fam." While they all share similar interests, they emphasize their individuality.

"We're not the same people. We're actually very different - like night and day, when it comes to some personality traits," Krissie said. "Yes, we look alike. Yes, we have very similar interests in things. But we are very different people."

Krissie had a bridal shower a week ago, noting it was the first party she's had just for her. They "just do things in twos," Kassie said.

The couples have never heard of identical twins marrying identical twins. They wouldn't be surprised to find it, though, as they hope to attend the Twins Days Festival in Twinsburg, Ohio someday - which is billed as the largest gathering of twins in the world.

The festival is scheduled in accordance with National Twins Day every year. The Beviers and Lewans can't attend this year, however. Coincidentally, it happens to fall on Aug. 3 through 5.