In the short clip, Perlman and Dunbar walk briefly toward the camera before embracing and slow dancing.
Jonathan Bennett had risen to fame in his teen years when he was cast as Aaron Samuels in the film Mean Girls.
A source also confirmed that the incident took place on March 11 in Georgia where AMC is filming the final season of the long-running series.
The notoriously private couple had last hit the red carpet in 2014 at the Tony Awards.
The diagnosis also encouraged Benjamin Bratt to focus on his own health.
Josh Hartnett stepped away from the spotlight to focus on his mental health.
