BRITNEY Spears’ ex-husband Kevin Federline claimed the singer drank alcohol during her pregnancy and did cocaine while breastfeeding.
Britney, 43, was married to dancer and actor Kevin, 47, from 2004 until 2007.
The former couple welcomed two sons together during their three-year marriage.
On October 21, Kevin is set to release a tell-all memoir titled You Thought You Knew.
In addition to his former wife, the book also covers Kevin’s journey to Hollywood and his big break.
According to The Hollywood Reporter, it features allegations including that Britney had drank wine during pregnancy.
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As well as this, Kevin claims that Britney did cocaine while their boys were young – leaving him concerned about their breastfeeding.
The Sun has contacted Britney’s reps for comment.
Kevin told The Hollywood Reporter: “Of course this concerned me.
“Anything that could possibly harm the child is concerning. So yeah, it was a bit shocking for me through some of those moments.
“But yes, that night at the record release party was really what set everything off. I realized that I needed to get into “protect my children” mode, is what happened.
“Like I said in the book, it’s not necessarily the extracurricular activities (i.e., drug use). I was concerned for my children.
“And eventually she filed for divorce. That was the actual breaking point in the marriage.”
Meanwhile, Britney has since clapped back at her ex-husband’s claims in a passionate social media post.
She shared to Instagram: “The constant gaslighting from my ex husband is extremely hurtful and exhausting.
“Relationships with teenage boys is complex. I have felt demoralized by this situation and have always asked and almost begged for them to be a part of my life.
“Sadly, they have always witnessed the lack of respect shown by their own father for me.
“They need to take responsibility for themselves.
“With one son only seeing me for 45 min in the past 5 years and the other with only 4 visits in the past 5 years. I have pride too.
“From now on I will let them know when I am available.
“Trust me, those white lies in that book, they are going straight to the bank and I am the only one who genuinely gets hurt here.”
Britney was seen reuniting with her rarely-seen son Jayden back in June, with a picture showing the teen towering over her.