You regain consciousness to find yourself secured to an apparatus, with numerous gadgets affixed to your body and limbs. A few appear to be tracking devices, while others are positioned in manners too awkward to articulate.
"Greetings, Earthling from Terra-234-t! Our apologies for the abrupt abduction, but we are in dire need of reproductive material capable of fertilizing our kind. By chance, you have been chosen to participate in our extraction initiative!"
It appears that an extraterrestrial requires your, ahem, 'genetic matter'.