Exactly who does the sexual service act and free use work (all the legal stuff)? I know this is a weird question but it bugs me

Not all of the freeuse settings I write use the Sexual Service Act as a mechanism of freeuse.  In the fictional world(s) that use the Sexual Service Act, it’s a law that all women voted yes on that allows all men (over 18) to use any and all women (over 18) for sex at any time. I will not actually ever write out legalese for this. The idea is that all women are willing at all times, even to the extent that they fought for the passage of a law to guarantee their right to be used by men.

For a general set of questions and answers about FreeUse, you can check the FAQ I wrote a while back: http://masterlovehurts.tumblr.com/post/169477795436/freeuse-faq

I write several different fictional worlds, most of which have some sort of FreeUse.