I also thought it was a reference to the "Four Fs" of evolutionary psychology where the final F is often switched out depending on the environment: Fighting, Fl

I also thought it was a reference to the "Four Fs" of evolutionary psychology where the final F is often switched out depending on the environment: Fighting, Fleeing, Feeding and... mating. https://en.wikipedia.org/wiki/Four_Fs_(evolution) https://en.wikipedia.org/wiki/Four_Fs_(evolution)