You open the door and there are space aliens! Big green ones! They're willing to give you a cure for cancer and the recipe for cold fusion, and in return, all they want is to perform an anal probe on you, in the privacy of your bedroom. However, their probing equipment is located on their body, somewhere around their hips. Do you take one for the team to improve the human race?
For those of you that said yes, you'd give up the anus for the good of your species, you're in mid-probe, and for some reason, the probe involves a lot of thrusting. When the probe is completed, they say the cure and the recipe will be mailed to you in 2-3 weeks. As they're leaving, you notice a zipper on the back of their necks. They walk over, not to a spaceship, but to a parked rambler on the curb. What do you do?
Why do you suppose space aliens are obsessed with anal probes?