The idea for Lamar Odom‘s upcoming tell-all memoir came to him in the most unlikely place: rehab. The former NBA star opened up to Life & Style exclusively about the autobiography is currently working on — that is sure to contain more than one Kardashian bombshell.

“In rehab,” he says, “is when I thought about writing it.” He went on to tease when fans can expect to see the book on shelves. “It’ll be out soon. Hopefully by the end of the year.”

MORE: Lamar Odom Admits He Was a “Scumbag” to Khloé Kardashian and Hey, at Least He’s Honest

In Touch previously reported that Lamar, 37, will be opening up about everything from his marriage to Khloé Kardashian, plastic surgery secrets, and whether O.J. Simpson is really Khloé’s real father. “[The book will cover] everything. Everything. It’s a free-for-all. [I’ll be] open about everything that’s been going on in my life, about the past,” he said.

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An insider continued, “Lamar is going to include never-before-told secrets about cheating, sex, and drugs, the booze, the pills, the cocaine, all of it… “[he] has nothing left to lose.” According to publishing sources, the athlete can earn as much as $10 million for his work.

However, we don’t expect Khloé and the rest of the family will be happy about his book — especially after they stepped in following his near-fatal overdose in a Nevada brothel in 2015. Khloé is currently getting ready for baby No. 1 with new boyfriend Tristan Thompson, and that includes house shopping.

MORE: Khloé Kardashian Is So Ready to Get Pregnant With Tristan Thompson’s Baby

“Khloé and Tristan have been looking specifically at baby-friendly properties in Bel Air and Beverly Hills,” a source told Life & Style exclusively. “They both feel great about where they are in their relationship, and they’re ready to have a baby together.”

Meanwhile, Lamar’s sobriety is questionable after he was spotted at the launch last week, “drinking a Hennessy cocktail and hitting on two blond women at once,” according to a waitress at the event. “He seemed like he didn’t have a care in the world.”

For more exclusive celebrity news, be sure to pick up the latest issue of Life & Style on newsstands now.