From Wiktionary, the free dictionary
From spank + -o.
spanko (plural spankos)
- (slang) A person with a fetish for spanking, usually but not exclusively sexual
1995 February 15, BlueEyeBoy, “Re: What is going *ON* here?”, in alt.sex.spanking[1] (Usenet):I guess the second is the behaviour that makes us spankos.
2007, Susan Kohler, Another Batch of Warm Buns[2], →ISBN, page 115:She was no fool; this man was seriously hot, a spanko, potentially a great spanko and really nice
Erotic spanking on Wikipedia.Wikipedia