These days, Kailyn Lowry and Jenelle Evans are the most bitter of enemies.
In fact, it often seems that the Teen Mom 2 co-stars can't go a day without throwing jabs at one another on Twitter.
But believe it or not, it wasn't always like this.
In fact, there was a time when Kail and Jenelle were not only friends, but kindred spirits.
Dive into the gallery below for a full run-down of how these two went from besties to rivals:
In the months after they both found stardom on MTV, Kail and Jenelle became close friends and bonded over their difficult circumstances.
In the early days of the 16 and Pregnant/Teen Mom franchise, Kail and Jenelle were among the most "at-risk" participants.
Always the Rebel
Jenelle's penchant for bad behavior became apparent very early on -- and her brushes with the law began before she was old enough to vote.
Troubles of Her Own
Like Jenelle, Kail clashed with her family beginning at a young age, but unlike Jenelle, she was in no way to blame for the situation.
Kail received little support from her alcoholic mother or other family members, and she came close to homelessness more than once, often relying on the family of boyfriend Jo Rivera for support.
A Bonding Experience
It was around that time that Jenelle asked Kailyn for a favor that would strengthen the bonds of their friendship ...
As you likely know, Jenelle has had quite a few brushes with the law, and on one occasion, Kail came to her rescue.
Kail the Hero
“I called outta work and picked her up from New Jersey when she was strung out on drugs," Lowry told The Hollywood Gossip of that incident. "I took her to the airport. MTV knew about this and didn’t film it
In the years that followed, Kail and Jenelle drifted apart but remained cordial and even posed for pics together at MTV events. Then, Kail decided to go under the knife for plastic surgery ...
For some reason -- even though she'd gone under the knife for cosmetic procedures herself -- Jenelle decided to throw shade at Kail for her decision to undergo a Brazilian butt lift in 2016.
Is It, Though?
"When your cast mates subtly throw shade at you... it's cool though," Kailyn tweeted in response to Jenelle's trash talk.
No Going Back
Yes, it really started out that innocuously. But as mild as that exchange seems compared to the shots these two take at each other now, from that point on, Kail and Jenelle's relationship deteriorated rapidly.
It wasn't long after that that Jenelle decided to torpedo what was left of her friendship with Kail by tweeting out news that Lowry was pregnant with her third child well before Kail was ready to make that announcement.
Foe Disguised as Friend
"Congrats on your pregnancy girl!" Jenelle tweeted, knowing full well that Kail hadn't gone public with the news. "Heard the news from the crew. Super happy for you. Having 3 is hard but totally worth it!"
Isn't It Ironic?
Ironically, it wasn't long after that that Jenelle sent a cease and desist letter to Kail, alleging that Lowry had been spreading untrue information about Evans.
The relationship between these former friends further deteriorated when Kailyn was among those calling for Jenelle's husband, David Eason, to be fired after he hurled bigoted slurs at TM2 fans on Twitter.
Kail doubled-down on her anti-Jenelle sentiments during this past season, calling on Evans to be fired following a road rage incident in which she pulled a gun on a stranger and endangered her own son's life.
Jenelle on a Rampage
Just this week, Jenelle slammed Kail for allegedly insulting her on her podcast, AND accused her of sleeping with Javi Marroquin just to get back at Briana DeJesus.
A Succinct Reply
Kail shot back using one of out articles. We're sure Jenelle will clap back in time, but for now, we're declaring Kailyn the victor.