At this point, there are so many Teen Mom memoirs that the books practically constitute their own literary genre.

You'd think fans would begin to get bored of reading about their favorite reality stars, especially since their lives are already so thoroughly documented on television.

But as Leah Messer's recent memoir reminded us, sometimes the most painful, life-altering events in the Moms lives never make it to air.

And it seems that's certainly true in the case of Mackenzie McKee.

Mackenzie was away from MTV for several years following the cancelation of Teen Mom 3, but ever since she was cast on Teen Mom OG, she's been an open book.

No pun intended.

Now, Mackenzie is following in the footsteps of Leah, Kailyn Lowry, and several other predecessors by releasing an autobiography.

Those who came before her offered shocking accounts of mistreatment they endured in childhood and beyond, but nothing could have prepared fans for the horrors that Mackenzie endured when she was too young to even understand what was happening to her.

Sharing her account of these traumatic experiences is surely a bittersweet experience for Mackenzie, as she reminded fans while promoting her book in Instagram this week.

"Look what just came in the mail today," Mackenzie wrote, alongside a photo of the first editions of her memoir.

"I am so excited. Five days left before it's on the bookstore shelves," she continued.

"I'm really excited to share all my stories that weren't on the show, and honestly a little nervous too,"

As part of the promotional campaign for the book -- which was released on Tuesday -- Mackenzie allowed the publication of an excerpt that details one of the most painful incidents of her childhood.

McKee says she was "repeatedly" molested as a young girl, and the book offers a detailed account of how she was taken advantage of at the age of 4 by a neighborhood boy who was 8 years her senior.

She writes:

“We often played together, and one day, he told me we were going to play a new game where we would pretend to be dogs.

“We began imagining that we were puppies, and he told me I would have a special role to play. I was going to be the mommy dog, and he would be the daddy dog.

"'Mommy dogs,’ he explained, ‘didn’t wear pants,’ and he pulled me into the closet and shut the door where no one could find us. 

“I was the mommy dog, and I had to do ‘puppy things’. The boy did inappropriate things, and this happened a few times. I was confused, but I played along since I wanted so desperately to be liked.

“Quickly, I realized this was a different type of wrestling than the one I played with my siblings back home.

"Things went in a direction that made me uncomfortable, even though, at that time, I knew nothing. He did it nearly every time I visited. 

“One day, he asked me if I wanted to wrestle, and I told him no. With fire in his eyes, he yelled at me, ‘No! You are going to wrestle with me whether you want to or not.’

"I had never seen him react so angrily and strongly when I refused to play other games, and I wondered why wrestling was so different. After I wouldn’t wrestle with him that time, he never wanted to play with me again. 

“I didn’t understand why, but I figured that saying no to wrestling must have been the problem, but I didn’t know what I could do to make him like me again. 

“I later realized how damaging this is to children. We learn at a young age that people will throw us away if we stand our ground.

"It also ruins a child’s self-esteem, and later in life, that grown child has difficulty seeing where this loss came from.”

Mackenzie adds that she didn't understand exactly what sort of abuse had occurred until years later when she and a friend happened upon a pornographic scene on television.

“Neither of us had ever seen anything like that. In fact, we didn’t know that sex even existed," she writes.

"What we saw on TV seemed weird and gross to us, but out of curiosity, we didn’t change the channel. As the movie went on, I started having flashbacks of the puppy game and wrestling," Mackenzie continues.

“I felt a sense of extreme discomfort wash over me as I realized that what we were watching was an awful lot like the puppy game and the wrestling that the older boys had convinced me to do when I was younger.

"Even though my friend and I giggled uncomfortably, what was happening in the movie seemed naughty and wrong."

Mackenzie recalls that the discovery revealed a new layer of pain, as she realized that she had been forced into a situation that no child should have to endure.

“It was something reserved for adults, and certainly not something you should force on someone. ‘That’s been done to me before; I thought to myself in horror. ‘I’m not a good human. I’m not as pure as my parents think I am,'" she writes.

"I’m not innocent. I’m dirty and gross, and that’s why they like my siblings more.’ I felt like I finally had an answer for being different—I had been ruined.”

Yes, like so many victims, Mackenzie's initial response was to blame herself.

“I couldn’t tell my parents what happened. I couldn’t tell anyone. In fact, this is the very first time I’ve shared these stories publicly," she writes.

Mackenzie goes on to say that in sharing her story, she hopes she can help other victims understand that they are in no way at fault.

"I kept this in for so long, but I felt this was the time to share, because maybe my experiences could help someone else who has gone through something similar," she writes.

"Neither one has ever talked to me about what happened or apologized. Maybe they don’t remember it happened, or maybe they believe I was too young to remember," Mackenzie says of her abusers.

“Regardless, I don’t think for a second that they live with the knowledge that what they did changed my life forever and contributed to losing my self-respect and lowering expectations for myself. I thought I had lost all my value as a human being. I had been abused."

Mackenzie ends the account on a somewhat hopeful note, revealing that she no longer blames herself, and she hopes to help other victims come to the realization that they are in no way at fault.

“Anyone who’s gone through this should know that there’s no need to carry shame and guilt for something that others did to you," she writes.

"I sometimes wish I would have gotten help sooner instead of bottling this inside and letting the pain come out in sinful behavior. But like I always say, our struggles mold us into the strong people we become.”

During her time on MTV, Mackenzie lost her mother to cancer and endured a painful divorce and reconciliation.

But until now, no one knew that her childhood was filled with the sort of horrors from which most people never recover.

We applaud Mackenzie for being so open about her experiences, and we wish her all the best in her continued recovery.