Kim Kardashian and her sister Khloé Kardashian have always shared a love/hate relationship. In fact, they once admitted that they love each other and they hate each other quite often. However, the newest episode from E!'s reality TV show "Keeping up with the Kardashians" suggests that tension is simmering between the two sisters again.

In the promo for season 10 episode 16, Kim is privy to Khloé's conversation with ex-husband Lamar Odom. The reality TV star looks on as Khloé blushes and smiles when she's on the phone with the former basketball player.

Kim Kardashian says, "I don't know why Khloé and Lamar are talking but he hurt her so badly. As a big sister, I'm just really protective and for her just to be flirting with him on the phone makes me, like, sick to my stomach."

Although Kim confronts her sister about talking to Lamar Odom, Khloé brushes it off.

A few episodes ago, 31-year-old Khloé had revealed her relationship with her ex-husband and said that she still cares and loves him deeply. She said, "Things happened but that doesn't just stop me from caring about him or loving him, so if I feel the need to check on Lamar, that's my prerogative and I'm going to do it."

Khloe Kardashian and Lamar Odom tied the knot in September 2009 and their divorce was finalised in July 2015.

"Keeping up with the Kardashians" season 10, episode 17 airs on Sunday, 4 October at 8pm on E! You can live stream the episode via E! Live.

Watch the preview clip here: