exercise the ferret, v. — Green’s Dictionary of Slang

exercise the ferret v.

also exercise one’s pecker, exercise the armadillo

[SE exercise + chutney ferret under chutney n./pecker n.² (2)/fig. use of SE armadillo]

to copulate.

a.1952		in E. Cray Erotic Muse (1992) 32: God bless your soul / Let me exercise my pecker / In your hairy ass hole.
1963–74		B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 34: I haven’t even exercised the ferret yet.
1988		J. McDonald Dict. of Obscenity etc. 67: Another recent Australian one is exercise the ferret (or armadillo).
1989		J. Morton Lowspeak.
1991		Age (Melbourne) 7 Dec. 130/5: Australia has much of which to be proud [...] sink the sausage, exercise the ferret and flog the lizard.