Credit: MTV

Things between Mackenzie Douthit and her boyfriend Josh McKee aren't going so well on Teen Mom 3 (don't worry, though — they've since worked things out and even have another baby on the way!), and during next week's season finale the situation only gets worse. Things come to a head during a drive through the country when Josh gets so frustrated that he pretty much threatens to leave his baby mama on the side of the road!

"I'm about halfway from just pulling in and … " he starts when Mackenzie interrupts with, "and giving up on us?"

"I don't know," he responds, clearly fed up with their constant arguing.

But Mackenzie's not backing down — she wants an answer, and she wants it now. "You don't know if you want me, admit it," she says. "If you would put as much effort as I would into this relationship, I think we'd work out. If you loved Gannon in the ways I love Gannon, trust me, Josh, you would work it out."

Mackenzie's pestering doesn't sit too well with cowboy McKee who snaps back, "Why don't you shut up?"

At this point, Josh's cell phone starts ringing and Mackenzie grabs it to see who's calling. When he asks for the phone back, Mack stirs the pot even more. "Scared I'll see something?" she asks.

In a fit of rage, Josh yanks the phone from her hands and yells, "Get the f— out!" as he pulls over.

Will he actually leave her on the side of the road?! Check out this dramatic sneak peek clip and tune in to Teen Mom 3's Season 1 finale on Monday, November 11 at 10 p.m. ET to find out.