Jeff Bezos shared a rave review for “The Fly Who Flew to Space,” the new children’s book by his fianceé, Lauren Sánchez.

Bezos titled his review “Six stars” on Amazon, where the book has garnered 4.8 out of five stars since its release earlier this month. The story follows a young fly named Flynn who dreams of becoming an astronaut and goes on a space-themed adventure when they board a rocket ship.

“This is the best children’s book my fiancée has ever written,” he wrote in the review on Wednesday.

Bezos’ praise for “The Fly Who Flew to Space” came one day after Sánchez’s former yoga instructor filed a lawsuit against her in Los Angeles Superior Court.

The instructor, Alanna Zabel, said in the complaint that Sánchez stole her intellectual property and used it as the basis of her book.

“Defendant Lauren Sánchez, who had previously expressed oral and written interest in collaborating with Plaintiff, subsequently used Plaintiff’s book concept without Plaintiff’s consent or authorization,” the complaint says.

Zabel is also accusing Sánchez of intentionally inflicting emotional distress

The complaint says Zabel is a private yoga instructor in California who worked with Sánchez from 2007 to 2010. Zabel has authored children’s books that are available for purchase on Amazon.

The two women engaged in verbal and written discussions “spanning 16 years” about a “potential partnership to write a children’s book,” the complaint says.

“In 2022, Plaintiff reached out directly to Defendant via email, text, and Instagram, sharing a specific book concept with Defendant, about a cat who flies to Mars, re-opening prior discussions (from 2007-2010), and trusting her with the intellectual property and concept,” the complaint says.

The complaint says the email also revitalized conversations about a partnership between the two, including promoting Zabel’s children’s book “Dharma Kitty Goes to Mars,” which would involve giving the proceeds to Bezos Earth Fund and Bezos Academy.

The complaint says Zabel published “Dharma Kitty Goes to Mars” in 2022 and made it available for purchase on Amazon in 2023. Sánchez discussed plans to write a children’s book about a fly going to space during a 2023 interview with The Wall Street Journal.

“Defendant Lauren Sánchez, who had previously expressed oral and written interest in collaborating with Plaintiff, subsequently used Plaintiff’s book concept without Plaintiff’s consent or authorization. This theft of intellectual property occurred after years of discussions,” the complaint says.

Zabel said in the court filing that she stopped working with Sánchez in 2010 and that Sánchez’s actions were in retaliation.

“Defendant’s actions stemmed from her relationship with Plaintiff, who was her private yoga instructor and friend, which Defendant exploited to gain an advantage in her creative and professional business,” the complaint says.

Zabel — who court documents say issued two cease and desist letters before filing the complaint — is requesting a jury trial.

“As a self-funded female entrepreneur who has poured tireless efforts into building my business, it is profoundly disheartening to imagine someone in a position of privilege and influence—who publicly advocates for social issues, equality, and women’s empowerment—disregarding the dedication, creativity, and value of an individual who generously shared their ideas, innovations and projects,” Zabel said in a statement to Business Insider via email.