Kourtney Kardashian and Kim Kardashian West were constantly disciplined for wearing lipstick to school.

Kourtney Kardashian

Kourtney Kardashian

The 37-year-old 'Keeping Up with the Kardashians' star has admitted her and her younger sister would drive their teacher "mad" by breaking the rules and wearing makeup to their all-girls Catholic school, although they felt liberated when they were allowed to experiment with beauty products on a trip.

Speaking to PEOPLE about her rule-breaking beauty tricks, the Armenian beauty said: "Kim and I went to an all-girls Catholic school in seventh and eighth grade, and we started wearing dark lipstick to school. Our teacher would get so mad.

"I remember we went on a school trip to France, and they let us like use lipstick and we were like, 'Ah, this is like freedom!' "

It was Kourtney and 35-year-old Kim's late father Robert Kardashian who encouraged them and their younger sister Khloe, 31, to experiment more with cosmetics, and gifted them make-up lessons for Christmas.

She explained: "For Christmas one year, my dad got Kim and I these makeup lessons. They taught us how to do our own makeup, so I feel like we were always good at doing our own makeup. We've always been into it."