Green’s Dictionary of Slang

a fellator (thus generic for a male homosexual) or fellatrix.

1904		Number 1500 Life In Sing Sing 248: Fluter. A degenerate.
1931		Irwin Amer. Tramp and Und. Sl. 201: The men and boys who persist in singing or reciting this muck are regarded as ‘mousers’ or ‘fluters’ and as such avoided.
1941		G. Legman ‘Lang. of Homosexuality’ Appendix VII in Henry Sex Variants.
1950		Goldin et al. DAUL 72/2: Fluter. See Fag.
1965		Guild Dict. Homosexual Terms 16: fluter (n.): A fellator, as used by heterosexuals. (Rare.).
1977		Maledicta 1 (Summer) 16: The disliked person is accused of being a fag (or Three-Letter Man), a faggot, a fairy, a pansy, a queer, a fruit, a fluter, or the Queen of the Flits in Hoboken.