Autochroisexual is when you can have no desire to have sex with others or participate in sexual acts, and still have your body react in a sexual way. Think of it as watching and enjoying porn, but not feeling a desire to participate. It's on the asexual spectrum.
"They can watch porn and feel a stimulation in their nether regions, but they do not want to have sex with other people. Therefore, they identify as Autochroisexual."
by Jabba the Trump February 12, 2016