Britney Spears shades her ex-husband Kevin Federline’s failed attempt at making it as a rapper in her forthcoming memoir, “The Woman in Me.”

The “Toxic” singer savagely writes, “Bless his heart” while reflecting on K-Fed taking his short-lived rap career “so seriously,” Us Weekly reported Friday.

Spears, 41, also touches on the public “doubting” Federline’s musical talents during their marriage, according to the magazine.

Federline, 45, notoriously debuted his first song, “Y’all Ain’t Ready,” in 2005 followed by the critically panned “Popozão.”

He then dropped his first — and only — album, “Playing with Fire,” in 2006.

A Rolling Stone reviewer wrote that “Federline’s rhyme flow is the opposite of tight,” while a Slant Magazine critic opined that the album was “just as disposable and dumb as you’d expect.”

Meanwhile, a Billboard writer jabbed, “In general, Federline enunciates well.”

Federline’s music career was a far leap from Spears’ own success as a chart-topping pop superstar.

The Grammy winner and the former backup dancer married in October 2004.

Over the course of their union, they welcomed two sons: Sean Preston, 18, and Jayden James, 17.

The pair announced their separation in November 2006 and finalized their divorce in July 2007.

While the exes co-parented their children for years, Preston and Jayden lived with their father full-time during their mother’s fight to end her 13-year conservatorship in 2021.