Sources close to Lamar tell TMZ ... he wants to rekindle what he once had with Khloe and he thought Friday's comment on Khloe's IG post was a perfect time to get her attention, seeing as she's not with Tristan anymore.
As you know ... Lamar left a "hottie" comment on Khloe's outdoor shower pic, which drew Tristan's ire and a seemingly threatening response to Lamar.
We're told Lamar wasn't trying to be disrespectful, he just figured it was fine to shoot his shot because Khloe and TT are broken up again ... after new allegations he was cheating.
Lamar and Khloe were married from 2009 to 2016 ... and our sources say he thinks Tristan is fumbling the bag with Khloe. Quite frankly, we're told LO wanted to see where his comment might lead the exes.
So far, it hasn't led anywhere -- Lamar's had no dialogue with Khloe or Tristan. Not yet.