Maybe I'm just lost today, but on P411 there is Agency, Independent, and JFF.  Can't for the life of me figure that out.
Just Facebook Friends?  Perhaps.

Maybe it means Just For Fifty (dollars)?

Just For Fun?

Haha, that's exactly what I thought at first actually. But in the context of where he said he saw it, I kinda don't think so anymore.

Just Friendly Fucking.

I would have to read the sentence/paragraph to break it down. but Just for fun is what I am guessing. I usually google those and they come up. but what I can't find is   What is a blue shower?   Never heard of it, google doesn't help.    Anyone?

Blue toast is having the monger use mouthwash before getting intimate. I never heard of blue shower though. Could be another way of saying the same thing? Weird.

The JFF is right at the top... where it other wise would say Independent, Agency, then... JFF.  

Yup. And if you scroll through enough search results, you'll see it there as well; not just on profiles. In the same header spot, you'll see other names like secret playdates, LVC assistant, Posh booking assistant, Dreamgirlsaz, and so on. Seriously, it's the name of an agency.  If you want to know why that's their name, or exactly what their name means, I guess you could contact them?