Kim - who is married to rapper Kanye West - believes it would be a good idea for the former couple to meet in person.
"I think it would be nice if you guys had a face-to-face after all these years," the KUWTK star admitted, before adding:
"I just feel like maybe you have to get that out."
Khloe met and married Lamar in 2009 following a whirlwind relationship.
In 2013, however, Khloe filed for divorce from Lamar, but she withdrew the documents after he was found unconscious from a near-fatal overdose in a Nevada brothel.
There was speculation that the celeb couple reconciled during his rehabilitation, however, they eventually finalised the divorce in December 2016.
"I always felt after, I think this overdose, that I did everything in my power to be there through sickness and health," Khloe said in the teaser for the new episode.
"Once I saw that he, you know, wasn't in the headspace to really want to change his bad situation then I was fine letting him go."
While the Good American founder said "never thought twice about" the situation and why they ended all communication, she admitted it was nice to have "a decent, nice conversation with Lamar."
However, the 35-year-old revealed that she is at a loss at what to do in a piece-to-camera.
"I don't want to mislead him in any way, but I would like to meet with him," Khloe - who shares daughter True Thompson with NBA player Tristan Thompson - confessed.
While Kim offered to join her sister for the catchup with her ex-husband the reality star still seemed hesitant.
Sunday's episode of Keeping Up With the Kardashians appears to largely focus around Lamar Odom and his relationship with the entire Kardashian family.
Khloe has finally read her ex-husband's autobiography, Darkness To Light, which was released earlier this year, and what she found in its pages sparked a huge fallout with her mother, Kris Jenner.
In the clip shared on E! News, a visibly upset Khloe tells her sister, Kylie Jenner:
"In the book, I found out that mom's lying to me."
The clip wraps up with Scott Disick saying how worried he thinks Kris is after the revelation.
"She literally thinks you’re gonna, like, come for her," he told Khloe.
And her response: "Guess what? I am."
The next episode of Keeping Up With the Kardashians airs on Sunday at 9 p.m. on E!