Origin of “FWB”?

[Curiouscouple2469]

I dated a girl for a while when we were teens then we went separate ways but called her up from time to time and would hook up for a quickly…
We eventually both got married but every so often would reconnect for a quickly for old time sake.
Forty some odd years later we are both divorced but with other partners but we have from time to time hooked up for a quickly when I am in town for older time sake.

So a FWB definitely and always willing to prove that point.