Fuck-nut; the rated R version of "loose cannon" is an insult implying that the recieving end is incapable of basic human thought, therefore indicating a need to be insulted. This is where "fuck-nut" comes in. Walk up to this "individual" and as if a magician saying abbracadabra, say it straight to their dumb fucking face.
While our lifespan is the number of years we will live, our healthspan is the number of healthy years we will have and our sexspan is is the number of years we will continue to be healthy enough to continue having an active sex life.