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3.
A Tandem Bike is a bicycle with two seats and two sets of pedals, allowing a couple to ride together. Requiring as much team work as a trust fall, but with fast moving traffic to fall in front of when it fails. A good way to test how strong your relationship is.

On conventional tandems, the front rider steers as well as pedals the bicycle and is known as the captain, pilot, or steersman; the rear rider only pedals and is known as the stoker, navigator, or rear admiral.

The term Tandem refers to the arrangement of the riders one behind the other rather than the number of riders. Bicycles for three, four, or five riders are referred to as "triples" or "triplets", "quads" or "quadruplets", and "quints" or "quintuplets" respectively. One such familiar to UK TV viewers was the "trandem" ridden by The Goodies.
1. That's an awesome Tandem Bike, but you should know that your woman on the back isn't peddling.

2. I was riding my Tandem Bike, and she must have been working harder because it was easier to peddle. Then I realized that she Fell off my bike

3. Your car has broken down! Don't worry, there is a spare seat on my Tandem Bike. Just sit down, put your feet on the pedals, and don't lean to the side while peddling.
by AussieGeoscientist March 17, 2011
 
1.
(N.) A group of women who are on same menstrual cycle.
"After working here for three months, it was only a matter of time before I was added to Mary and Ashley's tandem bike."
by Leon Firestone December 29, 2012
 
2.
An FMF threesome where one woman rides the dick while the other woman rides the man's face.
The threesome fantasy was complete when ladies laid him on his back and rode him like a Tandem Bike.
by Jamalizm August 04, 2010
 
4.
Referring to someone who has been fucking two best friends, either consecutively or simultaneously. Can be a girl or guy.
Have you heard about her? After she broke up with Josh she started fucking Will.
Yeah, she's a tandem bike
by whatevvs666 May 01, 2011