Jett and Jax are ‘Cousins, Brothers and Twins’ and We Have Questions!

What happens when twin sisters and twin brothers procreate? They make two adorable little baby boys!

Case in point?

Jett and Jax Salyer, the two cheeky sweeties in the photo below, who are not only cousins but also genetic siblings and quarternary twins. 

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Two peas in a pod: Jett and Jax. Source: Instagram

Let’s start at the beginning, shall we? 

Once upon a time, in America in 2017, identical twin sisters, Brittany and Briana met identical twin brothers, Josh and Jeremy Salyer at a music festival.

Twins marry twins 

The Salyer brothers proposed to their ladies six months later and they had one big gigantic wedding to celebrate in 2018.

They now all live in the same house in Virginia, US, and fell pregnant within weeks of each other. 

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The twins admit to doing everything together, including falling pregnant. Source: Instagram

Now, it might seem a little bit crazy for twins to marry twins but this actually happens more often than we thought. According to Futurism, there are about 250 marriages like this on record.

Unsurprisingly, these couples may even go on to have identical twins of their own. But, for Josh and Brittany and Jeremy and Briana, both couples were blessed with one baby each – Jett and Jax! 

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Pretty sure this is just a mirror image but Instagram informs me otherwise. Source: Instagram

Living A Twinsane Life

The Salyer foursome shares their daily antics with their fans on Instagram and have admitted that falling pregnant at the same time was planned. 

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Source: Instagram

While Brittany and Josh were aware that they were having a little boy, Briana and Jeremy decided to wait until the birth to find out.

Of course, they were over the moon to discover they would be raising baby boys together. 

‘Our children will not only be cousins, but full genetic siblings and quaternary multiples!’

Now, we all understand how Jett and Jax are cousins. But the couples have also shared that their children are ‘”full genetic siblings” and “quaternary multiples” and we’re pretty sure these are just made-up terms. 

But, they’re actually not.

From a genealogical point of view, yes, Jett and Jax are cousins. 

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Source: Instagram

However, their DNA would be hard to distinguish from that of full genetic siblings and thus, if the boys were to take a DNA test, they would be found to be brothers. 

Identical twins share the exact same genetic material, egg/sperm and all (while fraternal twins are conceived from a different egg and sperm). So in this case, the four “sets” of DNA are the same as only two sets,” Futurist explains.

Now, for the quaternary multiples thing? 

This comes from the type of marriage the foursome have. You see, when twins marry twins, it’s known as a quaternary marriage. 

Quaternary multiples and quaternary twins are the terms used to describe the offspring of couples made up of two sets of identical twins.

As the Salyers explain on their Instagram page,

Quaternary Twins: Two children born less than nine months apart to identical twin mothers and identical twin fathers. Such children are not only cousins, but also full genetic siblings who are the same age…making them a very rare type of sibling-set.” 

So there you go. Cousins. Genetic siblings. Quaternary Twins. 

Whatever the case, the boys are too cute for words and many of the Salyers’  fans cannot get over how identical the boys look.

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Source: Instagram

What do you think? Could they pass as identical twins? 

What to read next

Avatar of Jenna Galley

Born and raised in Canada, Jenna now lives in Far North Queensland with her tribe. When the mum-of-three is not writing, you can find her floating in the pool, watching princess movies, frolicking on the beach, bouncing her baby to sleep or nagging her older kids to put on their pants.


  1. Avatar of Blossom

    Imagine when the babies start school. How do the parents which child is theirs when they are playing together, especially when they are old enough to trick adults by both answering when one of them is called or spoken to – or the teacher. I know of a case where a family took care of identical twin girls. They had a little bracelet on one of the babies.
    The foster Mother couldn’t distinguish the difference in the babies’ cries. Their son noticed that one of the baby’s had a deeper cry than the other one did and able to tell him Mum which baby had woken up.
    The only difference I can see in these 2 babies is they have a slightly different shaped foreheads.

  2. Avatar of Chris

    I know a set of twins who are also cousins. Their mother was struggling to conceive and her sister donated her eggs for the couple to use for IVF. A single embryo was viable and implanted. At their first scan there were two heartbeats and they thought it split. Except the twins are boy/girl. So they spontaneously conceived during the IVF cycle for a literal buy one get one free situation. They’re refusing to do DNA testing to find out which child is which.
    There’s already a term for fraternal twins with different fathers, heteropaternal twins. But science has literally made it possible for heteromaternal twins to be a thing! Which I think is so cool.

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