It often seems that Jenelle Evans and Kailyn Lowry have been feuding forever, but the bad blood between these co-stars is actually a relatively new development.
They were never exactly besties, but it seems Kail only realized that Jenelle is bad news in early 2015 -- around the same time that many Teen Mom 2 viewers realized that Jenelle is a lost cause with no desire to reform.
You see, Evans is no victim of circumstance and deserves no sympathy.
She's not a troubled young woman trying to make her way in the world; she's an agent of chaos seeking to drag others down to her level.
And lately, she's been attacking Kail in an effort to distract from much more serious issues in her life.
1. Happier Times
There was a time when Kail put real effort into forming a friendship with Jenelle, but eventually, she came to the realization that Jenelle is beyond help.
2. A True Friend
At one point, Kailyn even helped to bail Jenelle out of jail. Presumably, this was before she realized that Jenelle has no intention of changing her ways and will continue to get locked up until they eventually throw away the key.
3. The Decline
The friendship between the co-stars deteriorated gradually, but the point of no return seemed to be when Jenelle told the world Kail was pregnant with her third child.
4. Cold War Turned Hot
At the time, Lowry was not ready to go public with that news, and ever since, she and Jenelle have not minced words when discussing one another publicly.
5. It's On
After that, it was a no holds barred throwdown between these two, and a pattern quickly emerged.
6. The Strategist
When Jenelle gets bored or needs something to distract from her increasingly dysfunctional personal life, she simply lobs a social media grenade at Jenelle. Last week, we saw a prime example of this phenomenon ...