As a filmmaker, he captured some of ACT UP's most memorable moments, including the action we worked on together putting a giant condom over Jesse Helms' house. Robert's most famous work was Stop the Church, documenting ACT UP's December 1989 demo at St. Patrick's Cathedral. In 1991, the film caused its own demonstrations and controversy when the head of PBS programming pulled it at the last moment from a national airing on the series P.O.V. Various local PBS stations aired it in protest (see this NY Times story).
On a more personal level, he was the man that swept me off my feet at a moment in my life when I desperately needed someone strong and loving to hold me tight. I had just quit my Wall Street trading job thinking I had only a year or two more to live, and came out publicly as HIV positive during an ACT UP demo. Robert was HIV negative, and he helped me live and love without stigma.
In the picture below, he's meeting my family for Thanksgiving dinner. He had a mischievous side I loved, and in this shot he's giving me the evil eye for dragging him way out of his comfort zone. But the smile says "it's okay."
He always told me everything would be okay.