Are there many singles out there these days looking for F.W.B 's.?

Has to be the right person. Biggest thing is make sure up front that you're both in it for the same thing. You don't want to sleep with someone and then tell them afterwards that you only want to be F.W.B's. Typically that makes the person think that they did something wrong, the was bad, or you were simply using them. If you're honest about it things should work out ok.