I can't believe that until now there's no
definition.
Speed Sex is getting drove on large amounts of methamphetamine (speed) and having marathon sex featuring all sorts of strange, kinky, unusual acts resulting in a series of intense rushes that are equal to a regular orgasam and culminating in a hands-over-your-head rollercoaster
death-drop mind blowing
orgasm (hopefully). Hopefully because that big one can be very elusive and you might not get it but if you do... oh boy. Even if you don't it's still an E-ticket ride.