Boyz II Men Reunite With Rarely Seen Ex-Member Michael McCary In Surprise Reunion That Left Fans Stunned

Fans were shocked to see the former fourth member of Boyz II Men reunite with his group during their Las Vegas residency.

Although Michael McCary didn't perform with Boyz II Men — with members Wanya Morris, Nathan Morris, and Shawn Stockman at The Chelsea at The Cosmopolitan — he did hint at a possible reunion Friday.

"There will be another day that we'll all be onstage together, trust me. It's coming, and I love these guys," he said.

The 52-year-old, who had been dealing with back problems for two decades, was diagnosed with multiple sclerosis. "Multiple sclerosis (MS) is a chronic disease of the central nervous system," according to the Mayo Clinic. "It is thought to be an autoimmune disorder, a condition in which the body attacks itself by mistake."

He announced his diagnosis on OWN's reality show, 'Iyanla, Fix My Life.' The crooner left the group in 2003 and has remained out of the spotlight since.

McCary's bandmate Shawn Stockman, 51, addressed speculation around McCray's departure from the group, per 'PEOPLE.'

"Let me tell you something, all of that s**t is wrong. All of it [is] inaccurate, 100%," Stockman said before inviting his former bandmate onstage to a surprised crowd. "Yes, have we had our disagreements? Yes. Have we had our share of differences? Yes. But this man is still our brother and will always be our brother 'til the day we die."

In a 2014 interview with the 'Huff Post,' the remaining members shared that McCray's back problems were only a portion of why he left the group. The bass singer described his desire to return to the R&B band in 2012 but declined a contract that would protect the other three should McCary skip out again.

"Because he left us hanging so many times, we had to cover what we had been doing the last nine years he wasn't there," Nathan Morris, 43, said. "You can't just run out one day and don't show up. We had to have some sort of contractual agreement to make sure he was going to be there for everything."

In 1991, the group achieved commercial success with the release of their singles "Motownphilly" and "It's So Hard to Say Goodbye to Yesterday," both of which peaked within the top five of the Billboard Hot 100. Their 1992 single, "End of the Road" peaked atop the chart and set a then-record for 13 weeks at No. 1. The group, formed in Philadelphia, went on to break this record twice more singles "I'll Make Love to You" (1994) and "One Sweet Day" (1995) setting the records for most weeks at the top spot.

Per 'Billboard,' Boyz II Men was recognized as the biggest boy band from 1987 to 2012.

Boyz II Men, who won four Grammy Awards, continue to perform as a trio despite McCary's departure.

Their last studio album, 'Under the Streetlight' — their 15th — was released in 2017.

Boyz II Men's residency wrapped Saturday night and they will kick off their new tour on September 6.