AceShowbiz - Britney Spears isn't done unleashing her grudge against her mother. After refusing to accept her mom's apology, the pop star has now accused Lynne Spears of slapping her once for partying "so hard" with Paris Hilton and Lindsay Lohan, while her mother took care of her two sons, then-two-month-old son Jayden and one-year-old son Preston.

Reflecting on the unforgettable moment, the 40-year-old singer posted a clip of Jennifer Lopez slapping Jane Fonda in "Monster-in-Law". She wrote in the caption, "I swear I've never slapped anyone my whole life !!! I WOULD GIVE ANYTHING TO SEE WHAT THAT FEELS LIKE … JUST SAYING!!!"

"The first time I ever got slapped was the one night Paris [Hilton] and Lindsay [Lohan] dropped me off at my beach house with my babies," the so-called Princess of Pop recalled. "My mother was watching Jayden and Preston...yes I partied till like 4am and my mother was PISSED !!!! I walked in, she looked at me and hit me so hard that I will never forget it !!!"

"This was all 15 years ago … I mean we've all grown up since then !!!" Britney added, before concluding her caption with, "Psss since then I've always wondered what it must feel like to slap someone ... GUESS I WILL NEVER KNOW !!!! Stay classy folks !!!"

Earlier this month, Lynne had asked for forgiveness for "anything and everything" that has hurt her daughter. Reaching out to her daughter via the comment section on her Instagram account, she wrote, "I am soooo sorry for your pain! I have been sorry for years! I love you so much and miss you. Please unblock me so I can speak to you in person! Britney, deep down you know how much I love and miss you! I apologize for anything and everything that's hurt you!"

Britney, however, brushed off her mom's apology, telling her to "go f**k yourself." She wrote in a rant about her family, "Mom take your apology and go f**k yourself !!! And to all the doctors for f**king with my mind … I pray you all burn in hell !!! Kiss my mother f**king a**!!!!"