Noun. The distaff version of the femme fatale. (late 19th Century British slang usage; obsolete)
1. A seductive male, typically of homosexual or bisexual persuasion, who lures men or women into dangerous or compromising situations;
2. a man who attracts men or women by an aura of charm and mystery.
"Lord Alfred Douglas can be considered, using the Whitechapel slang of the time, the 'femme fatay' that did in Oscar Wilde."
-- Patricia Cornwell "Portrait of a Killer: Jack the Ripper - Case Closed" (2002)