Britney Spears alleged her mother, Lynne Spears, once slapped her "so hard" for partying with Lindsay Lohan and Paris Hilton till 4am.

Britney revealed she was already a mother of two at the time and her husband Kevin Federline had just left her.

She went out partying with Paris and Lindsay while her mother watched her sons.

The 40-year-old singer recalled on Instagram: "The first time I ever got slapped was the one night Paris and Lindsay dropped me off at my beach house with my babies.

"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 !!!"

Britney Spears recalls being slapped by her mother because she partied with Paris Hilton and Lindsey Lohan despite being a mum-of-two

Britney is currently estranged from her mother and father and has rejected attempts made by her mother to reconcile after they placed her in a conservatorship for 13 years.