Amber Portwood's ex-fiancé is seen taking a lie detector test during the finale episode of Teen Mom OG season 6B.

As fans prepare to watch the dramatic testing unfold, a sneak peek has been released which shows major tension between the couple.

As Matt Baier is asked, "Have you had any sexual communications with other women?" Portwood is seen showcasing her clear distrust of her fiancé.

"I'm about to freak out, I'm about to freak out!" she says, according to a report by Hollywood Life on Friday.

At the end of last week, Portwood spoke to Us Weekly about her decision to move forward with the lie detector test.

"I wasn't against it because I guess I kind of felt like I wanted to know," she said. "I was happy with some of the results...it clarified some things. I think people will actually be shocked with some of the results. Some of them actually pleasantly surprised me and made me feel amazing and I think it [will make] a lot of people look really stupid that [have] always been talking s**t."

"It still doesn't change the other problems that we had in our relationship and things that happened in the past like lying," she continued. "So there's a lot that needs to be worked on there for us to even think [about being] together."

While Portwood and Baier are not currently together, they could be soon.

In addition to Portwood telling the magazine that a reunion is up to Baier at this point, the magazine also confirmed the couple is currently filming Marriage Boot Camp: Reality Stars in hopes of getting their relationship back on track.

To see more of Amber Portwood and Matt Baier, tune into tonight's season finale of Teen Mom OG Season 6B at 9 p.m. on MTV. 

Tags: teen mom og MTV Reality TV Amber Portwood matt baier