Krystal's Previous Relationship on 'Love During Lockup' Ended With Assault and Prison Time (EXCLUSIVE CLIP)

The lives that the cast members on Love During Lockup had long before they were cast on the show are typically very different from what viewers see play out in the series. For Krystal and Sam, that's especially true since, well before the cameras came around, Krystal was arrested for assaulting her now ex-husband.

Technically, he was the reason for her incarceration, but in an exclusive clip ahead of the Dec. 13 episode, she openly admits to being the one at fault in the altercation. That was seven years before Love During Lockup, though. And now, Krystal and her husband Sam might be ready to start over as Sam gets to know his wife's family while she remains incarcerated.

In the clip, Krystal explains how she ended up in prison. And, although a good chunk of her 14-year sentence is now behind her, she still has some time to go before she is back on the outside. And it's all because, during an especially heated argument with her ex-husband, Krystal physically assaulted him with a knife.

"When I was 19, I fell in love with a guy," she explains in the Love During Lockup clip. "It was a very addiction-fueled volatile relationship. And my ex-husband and I got into a real bad argument and I assaulted him by cutting him on the forehead with a kitchen knife."

As a result, Krystal was sentenced to 14 years in a Texas prison, where she remains at the start of the show. She was charged with aggravated assault. It seems like Krystal has learned from her past mistakes, though. And now, she and Sam are ready to share their story with viewers.

In the clip, we also meet Sam, who explains that when he began to write to Krystal, it was because in doing so, he knew there were no strings or pressure attached.

"Shortly after I got divorced from my ex-wife, I wrote [to] Krystal off a website," Sam says. "And the plan behind it simply was just kind of, be able to write to somebody but not actually have to have any kind of obligation to it."

Now, however, that has changed, since Krystal and Sam's relationship progressed to marriage. While Krystal continues to serve out her sentence, Sam gets to know her family, primarily her grandmother, though Krystal isn't wild about that.

On the plus side, like Krystal, Sam has learned what not to do in a marriage because he was also married once before. His marriage didn't end in a physical assault and prison time, though. Instead, Sam explains in the clip, he and his "high school sweetheart" ended things when they both realized they were unhappy.

"It was better to get divorced than end up killing each other," Sam says.

Watch Love During Lockup on Fridays at 8 p.m. EST on WE tv.