Sean Sasser, of "The Real World: San Francisco," died at age 44, his friend and former castmate Judd Winick confirmed Tuesday.
"Our friend Sean Sasser has died. Our love goes out to his family &husband Michael," Winick tweeted. "We will miss u so much."
Sasser was introduced to the spotlight in the early '90s and known for dating his "Real World" costar Pedro Zamora. Zamora's battle with HIV and AIDS brought international attention to a then-taboo topic, which was covered at length on MTV up until his death at age 22.
Sasser, who exchanged rings with Zamora in a televised commitment ceremony, became an AIDS activist leading up to and after his costar's death.
He later became a pastry chef and found love again with partner Michael Kaplan. Kaplan told Queerty Sasser died of mesothelioma, a rare cancer of the lungs.
Our thoughts and prayers are with his family and friends.