McGowan, the curvaceous 27-year-old star of Jawbreaker and Ready to Rumble, and Manson, the 32-year-old antithesis to all things decent and morally upright in Puritan society, announced the news Thursday through her publicist.
In a brief statement, McGowan said, "There is great love, but our lifestyle difference is, unfortunately, even greater."
No word on what "lifestyle difference" presented the biggest problem: His glam-rock tendencies to prance around stage in corsets and war paint, or his recent sympathies to George W. Bush's presidential campaign.
Either way, the news comes almost two years after McGowan revealed to Howard Stern's radio audience that her goth boyfriend proposed to her two days before Valentine's Day (incidentally, while they were taking a bath). The couple had been together about a year prior to that.
Manson currently is in the middle of his Guns, God and Government tour to support his fourth album, Holy Wood (In the Shadow of the Valley of Death). Though his album sales have tapered off (what with parents more concerned about Eminem these days), the album caused some controversy last year when several retailers balked at stocking the disc because of the cover art, which depicted Manson getting crucified.
Meanwhile, McGowan, whose screen credits also include Scream, returns to theaters next month with Monkeybone, a combination live-action and animated comedy costarring Brendan Fraser.
McGowan also earned worldwide acclaim for her gratuitous show of flesh at 1998's MTV Video Music Awards alongside Manson. The pair also generated controversy by starring together in his video, "Coma White," in which they played president and First Lady for a reenactment of John F. Kennedy's assassination.