He was a writer and cast member of Saturday Night Live in the 1980s, co-wrote the 1989 film Shag, and has written for the television series MADtv, Hype, and Tripping the Rift.
[12] Sweeney also performed a stand-up routine for the special Coming Out Party in 2000, which centered on his rough childhood in the 1960s, how he explored his sexuality in the 1970s, how he tried to survive the 1980s with the AIDS epidemic, conservative politics, and being open about his sexuality when he was chosen to be a cast member for Saturday Night Live (making history as the first openly gay male actor to ever appear on a network TV show); and his post-SNL life, when he and Lanier Laney cared for Laney's mother, who had Alzheimer's disease and did not know her son was a homosexual.
The first, Nancy Reagan: It's Still My Turn (1990) which started as performance art piece at Highways in Santa Monica, and transferred to New York's the Actor's Playhouse Off Broadway.
In 2018 he appeared in two episodes of FX's Emmy Award-winning The Assassination of Gianni Versace: American Crime Story as David Gallo.
[14] Laney and Sweeney were also writing partners for Saturday Night Live during the 1985–1986 season, the film Shag, and the Syfy Channel cartoon Tripping the Rift.