Putting your penis's urethra right up to a girl's urethra and peeing, or vice versa. The pee goes up to the receiver's bladder so that they are all fueled up.
Mid-air Refueling is the act of space docking with the added bonus of diarrhea.
This is not true space docking, because the act resembles a refueling aircraft passing fuel to the other. A vaccuum seal is essential to success and cleanliness.
Replenishing your mixed drink before you finish so that you, your girlfriend, your wife or your friends cannot reliably count how many drinks you have had.