Farrah and her mother Debra are always trying new ways to work at their relationship -- from hypnotherapy to Debra supporting her daughter and granddaughter at milestone events (like store openings and New York Fashion Week). And during this week's episode of Teen Mom OG, the duo jetted off to Italy (Michael, his girlfriend Amy and Sophia were also present) to try to move forward from recent disagreements. But while the trip was filled with ups, the installment ended with a major down.

The vacation seemed to start off smoothly: Even though Debra was surprised to see her ex and his new girlfriend on the trip (the MTV grandmother was intentionally not told that Michael and Amy were coming), Farrah, Debra and Sophia went to a cooking class. As they whipped up a trademark Italian dish (gnocchi, to be exact), Farrah commented that the experience reminded her of being in her grandmother's kitchen.

But Farrah's fond family memories quickly faded -- and tensions between her and Debra escalated when they went out for dinner (with Sophia) post-cooking class. What went wrong? After Farrah said the "trip was going well" without Debra's fiancé David (Farrah and David have notoriously bickered), Deb quickly fired back.

"I think it's going great without Simon," she countered.

Farrah immediately took offense, and Debra insisted that Simon hurt Farrah and "lied." But Farrah brought the conversation back to David -- specifically, how he does not like her and how awkward her 26th birthday party was with him present. After Sophia wandered to look at the desserts, Farrah stated that Debra should not bring up Simon in front of the eight-year-old.

"I don't talk about it, so I hope that you would respect how I parent and how I do things. It's hilarious how you waste my time bringing up someone who is non-existent in my life so you can feel better about your own fiancé's sh**t," Farrah added.

Debra insisted that she wanted to move forward, but Farrah responded by calling Debra an "evil bitch." The conversation ended poorly, with Farrah telling her mother not to talk to her anymore and Debra saying the situation is "really sad."

It remains to be seen how the two will proceed in Italy -- and if they'll spend any more time together exploring and sightseeing. Do you think Farrah and Debra will be able to move on from this disagreement and enjoy the adventure? Or was the aforementioned fight the last memory they will have from their trip? Vote below, sound off in the comments, and to find out the aftermath of the disagreement, be sure to watch Teen Mom OG this Monday at 9/8c.