Kourtney Kardashian has taken to Twitter to explain to confused fans why she was seen drinking bottled water after giving her younger sister Kim a hard time for having the product in her office.

While the reality TV star's other siblings live-tweeted throughout Sunday's instalment of Keeping Up with the Kardashians, the mother-of-three chose only to share one post, as she responded to a fan's question over her mixed messages regarding single-use plastic.

"Love love love that @kourtneykardash gave @KimKardashian s**t for drinking bottled water and in the VERY SAME episode, she is seen drinking bottled water. So chaotic, I love it," the Twitter user wrote.

In response, Kourtney quickly replied, explaining: "I was in Kim's office and that's all that was there and no I'm not perfect, but I could have brought a reusable bottle for the day, this is true. #KUWTK."

It's not the first time the sisters have butted heads in recent weeks.

During a previous episode of the popular series, Kourtney and Kim fought over their daughters Penelope Disick and North West's joint Candyland-themed birthday party, with the elder sister wanting healthy treats for the bash over mother-of-four Kim's preferred sugary snacks.