The passing of a female companion after An alpha male (DB) has his way with her excluding all emotional ties, to a friend in the circle that has interest.

The safeguarding of Earth and other worlds from biological cross-contamination (i.e. billionaires with too much time on their hands).

Also known as “planetary protection.” Planetary protection / quarantine “reflects both the unknown nature of the space environment and the desire of the scientific community to preserve the pristine nature of celestial bodies until they can be studied in detail.”

There are two types of interplanetary contamination. Forward contamination is the transfer of viable organisms from Earth to another celestial body. Back contamination is the transfer of extraterrestrial organisms, if such exist, back to the Earth's biosphere.

The passback is a sex move. It involves one male and one female. This sequence of events, if properly executed, constitutes a passback:
1. The male ejaculates into the female's nose
2. The female snorts up the semen and "hocks" it
3. The semen is spat back into the male's mouth
4. The male spits it into the the female's vagina
5. The female must subsequently show evidence of proper execution—pregnancy or an STD, for example