one who inserts their penis into a cats asshole or vagina for lack of a real human to do it to. That can be caused by ugliness, a deformity in the penis, other defects unattractive to females, or just being plain bored off your ass.
That dude is a total catfucker, he couldnt get real pussy if he tried.
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.