On August 28, Amy Roloff and Chris Marek will exchange vows at the former's family farm in Oregon.

But while the mother of four and her long-time boyfriend will confirm their love for each other at this event in front of friends and loved ones, many observers are afraid of the opposite emotion taking center stage.

They're afraid of what will happen when Zach and Jeremy Roloff cross paths later this month.

Because, yes, both are invited to their mother's big day -- and, no, they are not getting along well these days.

For several months, Little People, Big World fans had taken note of how infrequently Audrey and Tori Roloff interact with each other.

These same fans had assumed there was significant bad blood between the in-laws.

But a source recently told The Sun that the aforementioned women are totally cool with each other (as evidenceed by this throwback photo) ... and their husbands have actually been to blame for the tension.

Unexpected, right?!?

"Tori and Audrey always got along with each other," an insider previously told this publication, adding in surprising detail:

"Zach and Jeremy got into a huge argument one day [and] everything changed."

What was the basis for this clash?

Simply a lack of respect, The Sun wrote, claiming that Zach was angry his brother wasn't showing him enough support.

"It exploded and there was a lot of mud-slinging, resulting in the two couples keeping their distance," concluded the source at the time.

Neither Jeremy nor Zach has commented on this allegation.

What we can say for certain, however, is that the siblings haven't hung out in, well... who-the-heck-knows how long.

But it's been awhile. Good luck finding a photo of the brothers together on social media at any point over the last year or so.

This will change at their mom's wedding, though.

"Everyone knows they haven't seen eye-to-eye in a long while, but there was never any question to invite one couple over the other," The Sun also reported this week.

"It could be incredibly awkward for them to spend all day at the same wedding, but the family would like them to get along more.

"It's been a long time since they've been close after the brothers fell out, and the women took sides, but things are getting a little better."

Audrey and Jeremy, of course, are expecting their third child.

Conversely, Zach and Tori lost a baby via miscarriage in March and have been unable to conceive in the months since.

This awkward situation hasn't helped the two couple reconcile, as you might imagine.

Hopefully, however, celebrating Amy and Marek's marriage will marrk a turning point for Zach and Jeremy.

"This could be a chance for them to finally put the past behind them and act like family again, and for the cousins to interact more," concluded the insider.

"Time will tell as to whether they end up totally avoiding each other, or the occasion pulls them closer together."