Khloe Kardashian and Tristan Thompson Not Back Together, Still Just Co-Parenting

Khloe Kardashian and Tristan Thompson are essentially operating as one parental unit, but that doesn't mean they're romantic again ... despite growing speculation online.

Sources close to the two tell us they're still operating as they have been for months -- as co-parents -- but Tristan lives near Khloe's place, so they're spending a lot of time together. Remember, they now have two young kiddos, and we're told it's important to Khloe that the kids get to spend as much time with Tristan as possible.

Another clue that things are good between Khloe and Tristan -- she was spotted driving around in one of his vehicles last Tuesday -- so they're sharing keys too. Our sources say the two are in a great spot as friends.

What's more, we're told Khloe let Tristan and his younger brother stay with her in the immediate time following the funeral for Tristan's mom. At the time, Tristan was getting work done on the roof of his home after some water damage ... so Khloe opened up her doors.

TMZ broke the story ... it was back in January when Khloe boarded a private jet to be with TT in Toronto after his mom's sudden death. At the time, our sources told us Khloe wanted to be there as a source of support and comfort for Tristan -- Kim and Kris eventually came too.

Clearly, the family bond hasn't broken between anyone ... as we continue to see the Kardashian family support Tristan, even sitting courtside to cheer him on with The Lakers.