Identical twin sisters Brittany and Briana told the U.S. Sun that they have experienced most of their lives together. That includes the moment they married identical twin brothers Josh and Jeremy Salyers in a joint ceremony.

Now, the twin couples are experiencing parenthood together, and their children share a unique bond.

The Salyers family went viral after social media caught on to the fact that both couples recently gave birth to sons.

Of course, little Jax and Jett Salyers are cousins. However, the young boys have even more in common. No, we're not just talking about the fact that their names both start with the letter "J."

As the children of two sets of identical twins, they're also genetically brothers. The happy parents (all four of them) explained the situation in a post on their shared Instagram account.

"Cousins, Genetic Brothers, and Quaternary Twins," they wrote alongside a photo of the young boys (who, unsurprisingly, look very similar). Check it out below:

You may be wondering how cousins could qualify as genetic brothers. Why do Jett and Jax have a better claim to being brothers from another mother than most?

According to Futurism, it all stems from the fact that both sets of parents are identical twins. When the Salyers twins got married, they had what is referred to as a "quaternary marriage."

Time for a science lesson: Identical twins come from the exact same sperm and egg. That means that the siblings' DNA is, you guessed it, identical.

In quaternary marriages, both couples have the exact same DNA. Thus, their children also have very similar DNA.

Futurism notes that, based on a DNA panel, it would be almost impossible to tell kids like Jett and Jax apart.

Right now the Salyers family and their "twinsane life" is getting plenty of attention on social media. It probably doesn't hurt that they reportedly live in the same house, which makes their situation even more... unique.

In an interview on TLC, Brittany and Briana revealed that they even worked together.

Watch them chat about meeting and marrying their identical Prince Charmings below:

The Salyers' unconventional parenting situation has turned them into internet celebrities. However, it's worth pointing out that their case is not unique. There are other examples of quaternary marriages.

In 2014, identical twin sisters Keyolla and Teyolla Loux married identical twin brothers Eric and Shawn Crow in a similar joint ceremony. Keyolla even wrote an essay about the wedding.

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