When did the term “body count” in reference to someone’s sexual partners come into use?

Basically the title? I see it online all the time these days people talking about the “body count” in reference to the number of sexual partners and it’s so confusing for me. I’m a big crime junkie. I listen to true crime podcasts and I watch documentaries about serial killers and stuff so when someone says “body count” the first I think is “how many people did this person kill?” And now people use it for sexual partners for some reason and idk why.