To say that Briana and Brittany Salyers are a lot alike would be the understatement of the century. The two sisters, who are both 35, are identical twins who married twin brothers on the same day in Twinsburg, Ohio. (Seriously, their joint wedding was held on the annual Twins Day Festival in 2018.)

But their similarities don’t just end there. Last year, the sisters also became mothers at nearly the same time, when they each welcomed baby boys just a few months apart. And now, thanks to the wonders of genetics, their little ones are more than just first cousins, they’re also technically siblings!

When you consider the timing of it all, it’s pretty remarkable.

But then again, Brittany and Briana have always been pretty in sync.

After all, they both met and fell in love with their husbands — Josh and Jeremy Salyers, 37 — at the same time. And when it came time to tie the knot, they both felt ready to take the next step together. So when it came to having children, it was no surprise they were on the same timeline.

“We were hoping that we would have overlapping pregnancies so that this would happen,” Briana recently told Today Parents. “We thought it would be really cool.”

By *this*, she means having “quaternary twins” — a phenomenon so rare, most people have never even heard of it.

It happens when two sets of identical twins pair up, and each set has babies at roughly the same time. Since identical twins share the same DNA, that means Briana and Brittany’s genetic codes are the same, just as Josh and Jeremy’s are.

So, when Jett was born in January 2021 and Jax was born that April, they were linked in more ways than one.

Legally, the two kids are cousins. But genetically, they’re basically brothers. (And if you really want to get technical, they’re also kind of twins!)

By now, the Salyers are well aware of how unique their situation is.

In fact, according to Briana, there have only been 300 or so “quaternary marriages” known in the history of the world. (Wow.)

Needless to say, the boys will both grow up incredibly close, just like each of their parents did. But even if there was any doubt that their bond wouldn’t be tight, the Salyers have made it pretty impossible for their boys not to be lifelong BFFs.

Believe it or not, the two families both live under the same roof in Virginia.

They also run a wedding venue site together and keep up a joint Instagram account, which has racked up more than 179,000 followers.

Of course, they know this isn’t everyone’s cup of tea. But they don’t seem to care what the critics have to say.

“It was something we all four wanted and when we got engaged, we all wanted it that way,” shared Brittany, who added that Josh and Jeremy “understand the twin bond like we do” and enjoy all of the together time they get.

That said, they do get their fair share of unsolicited comments.

“We try to ignore sociopathic stalker comments and just focus on the positive,” Brittany told Today. “Some people think we are really strange and others think it’s really amazing. We’ve gotten a lot of support and interest and we’ve been grateful for that.”

For now, they’re just focusing on themselves and their babies, who are surrounded by more love than most can imagine.

They’re also still in limbo about whether or not to each go for baby No. 2, or to quit while they’re both ahead.

“We are debating if we should go for one more pregnancy each or not,” admitted Briana. “We will make a decision pretty soon. The babies are still pretty young [and] we are trying to wait a little longer to see what to do.”