Hours after teasing the upcoming release of his bombshell memoir in which he plans to expose alleged wrongdoing in his famous family, Collin Gosselin took to social media to shade his mom, Kate Gosselin.

“I didn’t plan this at all, but coincidentally on the day of the official announcement of my book, it is Colleen’s birthday,” Collin wrote alongside a snapshot with Colleen Conrad — whom his father, Jon Gosselin, dated from 2014 to 2021 before tying the knot with Stephanie Lebo in November.

“She is the strongest woman I know, who stepped in at the toughest part of my life and CHOSE to be a mother to me,” Collin, 22, gushed in the caption.

“Happy birthday to my wonderful, hardworking, passionate, and I could go on… to my real mom ❤️ I love you so much.”

In the comments thread, the former reality TV star wrote, “The love you feel for a mom you were given is incredible. But the love you feel for a mom that CHOSE you is something so powerful. I am so fortunate ❤️ @colleen.conrad122 I love you so much 🫶🏼”

Conrad responded in part, “I’ll always be here for you and you are my son. I love you!”

A rep for Kate, 51, did not immediately respond to Page Six’s request for comment on Wednesday.

The post comes hours after the “Jon & Kate Plus 8” alum teased the release of his memoir, “In the Shadow of Eight,” due to hit shelves in October.

“This is not a story for entertainment, it is a story to instill responsibility in everyone to advocate and speak up against abuse, injustice, and the exploitation of children,” he captioned a montage of photos from his childhood.

“I not only poured my heart into this book for my younger self, but for ALL who have faced unfair and outright heinous acts as children. I am your voice. I stand with you. CG”

The book’s publisher released a synopsis on Wednesday, promising that the memoir will share the “never-before-told story of how [Collin] escaped and found his way back from the dark.”

The publisher also described the book as a “reckoning with the dark side of fame: the systems, the entourage, and the institutions that allowed one boy to be erased.”

The book’s cover features a throwback image of Kate holding her hand over Collin’s mouth.

Kate and ex-husband Jon, 49, also share 22-year-old sextuplets Aaden, Joel, Alexis, Hannah and Leah, and twins Cara and Madelyn, 25.

The famous family rose to fame on the TLC reality show, which morphed into “Kate Plus 8” following the former couple’s divorce in 2009.

Jon was ultimately granted sole custody of Collin, while Hannah eventually moved in with them, as well.

Over the years, Collin has slammed Kate with allegations of “child abuse and child exploitation” — including allegedly being zip-tied and locked in a basement before being institutionalized in 2016 — with Kate consistently denying the claims and defending her decision to place him into a behavioral health facility.

Madelyn publicly backed up her mother, accusing Collin of “physical violence,” which Jon and Collin have denied.

In an August 2025 social media post, Collin seemingly accused his mother of being instrumental in his estrangement from many of his siblings, with Kate cryptically responding to the drama in a social media comment, “he knows why…”

Amid the family feud, Page Six revealed in September that Kate is dating her former bodyguard, Steve Neild, and that the pair “have wedding plans.”

Kate previously denied an affair with Neild in 2009, telling People at the time of the media coverage, “They’re going to keep going, and they’ll make up stuff to connect the dots.”

Collin and Jon swiftly took to social media to blast Kate following the revelation. “Everyone says my dad and I are hung up on my mom. We are not,” Collin wrote via Instagram at the time.

“We have suffered the damage of a narcissist and cried together.”

Collin told Us Weekly on Tuesday that in his memoir, he’s “sharing what was really happening behind the scenes,” and that the memoir is “about truth, survival, resilience and finding my voice after years of being silenced.”