The stars were in Park City to attend the Sundance Film Festival and reportedly met at pop-up club Tao's on Friday night, January 25.
A source tells the New York Post's Page Six that the stars arrived "within 10 minutes of each other", and it didn't take long for the "If Beale Street Could Talk" actress to join Michael at his table.
"They were put at separate VIP tables, but Kiki quickly made her way over to Michael's table," an eyewitness said. "And they seriously never left each other's side. Canoodling (making out) to the max."
"She would have her hand on the back of his head rubbing it as he whispered in her ear and (he) kept kissing her cheek," added the insider, who insists it was "clear to everyone in the room that they were together".
However, their entourages are said to have made sure the rumoured couple was not publicly photographed as they got intimate.
Michael and Kiki later left the club at the same time, but they have yet to comment on the nature of their relationship.
The news emerges weeks after Michael and Lupita Nyong'o shut down long-running speculation suggesting they were more than just good pals, after forming a flirty friendship during the promotional tour for their blockbuster superhero movie "Black Panther" last year (18).
"We're good friends, honestly, we've known each other a really long time and respect each other and I love this girl to death," Jordan told Entertainment Tonight earlier this month.
"It's flattering at the end of the day," Nyong'o added. "I think it's such a rare thing to find people you have good chemistry with and for us to find each other as actors and get to work together; it makes the work richer that we truly enjoy each other's company on and off screen."