Thompson was seen getting close with the unidentified woman at PH-D Lounge, a popular rooftop bar in Manhattan, on Saturday night.
"I know we've had our differences in the past but my heart is broken for you sis", Rose wrote.
It's hard to tell what is happening, but you can see Thompson talking to a brunette woman.
"They were talking and being around each other all night".
However, we should definitely note another male was photographed at the lounge wearing a black jacket over a white hoodie, much like Tristan's outfit - but we was seen in the same video.
It was only a matter of time before Khloe Kardashian came across the many pictures and videos of her boyfriend and soon-to-be father of her child Tristan Thompson allegedly cheating on her with multiple women at a club.More news: Family of Zoe Fleming preparing to lay her to rest
The NBA player had the night off before playing the New York Knicks on Monday night. The "Keeping Up with the Kardashians" star is expected to give birth very soon, and now the event will likely be marred by the National Basketball Association star's infidelity.
Kardashian confirmed her pregnancy in December, thanking Thompson for helping her achieve her "greatest dream" alongside a photo of him cradling her growing bump. This is Kardashian's first child and Thompson's second.
Jordan and Tristan share a son together, five-month-old Prince.
The drama could spell the end of Thompson and Kardashian's 19-month relationship.
Tristan Thompson is deep in the Sunken Place, and now nobody wants him.
Khloe has been staying in Cleveland where she plans to give birth to her and Thompson's daughter.
Amid the reactions to the upsetting news on social media, there has been an overwhelmingly negative response that Khloé somehow "deserved" to have this happen to her.