Last week, we reported on the news that the co-parenting relationship between Maci Bookout and Ryan Edwards had somehow gotten worse.

The trouble began during the taping of this year's Teen Mom OG reunion show.

Filming for Maci's segment took place near her home so that everyone involved could participate -- but it seems that Ryan and wife Mackenzie Standifer refused to join the others on stage.

The stuff hit the fan anyway, as Ryan's parents, Jen and Larry Edwards, took the stage for the segment, and quickly butted heads with Maci and Taylor.

And what are all of these grownups fighting about?

Well, as usual, they're beefing over the 12-year-old boy who's stuck in the middle of all this.

If you've been watching TM2 this season, you know there was a good deal of debate over the birthday of Jagger, Ryan's son by Mackenzie.

Bentley reluctantly attended the party, even after learning that it would take place at Ryan and Mackenzie's house.

When he got home, he revealed that Ryan and Mack basically ignored him the entire time he was there.

So it came as a surprise to fans when Mackenzie posted the above pic from the occasion and pretended that everything went off without a hitch.

"Yesterday we celebrated Jaggy’s birthday! Safe to say we had a great time!" she captioned the pic.

"How could you not have a blast around this bunch? My [heart emoji] is full.

“The fact that you really posted this picture knowing that y’all didn’t even speak to Bentley the whole time he was there is sad,” a commenter wrote.

“The fact you honestly believe that is very sad,” Mackenzie responded.

Standifer's response was somewhat baffling, as it was Bentley himself who claimed he'd been ignored.

“I guess she’s calling Bentley a liar?” another person chimed in.

That's when things really got real.

The Twitter user Unghosted Code Red brought the exchange to Maci's attention, and for obvious reasons, mama bear was not pleased.

“Check out Mackenzie calling Bentley a liar on Instagram,” Code Red tweeted.

"Mackenzie is brave sitting on a couch responding to strangers on social media about my son, but still not brave enough to sit on a couch and talk to me at the reunion," Bookout replied.

The reports of the reunion altercation came to us courtesy of The Ashley's Reality Roundup.

“At first, MTV wanted Mackenzie and Ryan to square off in-person on the set with Maci and Taylor, but Ryan absolutely refused,” says a production source.

“Then they asked Mackenzie to go out on stage solo and film a scene with Taylor and Maci but she said no.”

And so it was that Mack and Taylor wound up sitting out there with Ryan's parents, Jen and Larry Edwards.

“Everything was OK until the very end of the segment,” the insider says.

“Maci kept giving vague answers and was making it clear that she was upset but would not say why.

"[Taylor] kind of got up and eventually asked Larry if he wanted to take things outside,” says the source.

“It didn’t get that far, though. Nothing got physical."

It seems Taylor didn't hold back, and instead told Jen and Larry exactly what he thinks of their son.

"He told them Ryan is a ‘piece of s--t’ and that he, unlike Ryan, has been there for Bentley for a long time,” the insider claims.

In response to media coverage of the situation, Taylor reached out to The Hollywood Gossip to confirm that the situation nearly came to blows.

“You’ll have to see the reunion play out on TV but one thing I am always going to do is stand up for my wife and kids,” he said.

“You come for my wife and kids? I’m coming for you.”

Needless to say, this is one situation that will probably get worse before it gets any better.

And it seems that Maci has no intention of mincing words when it comes to her feelings towards Ryan and Mackenzie.

Those two really crossed the line this time.