Collected from various Bike Forum areas:

Wherever your relationship is heading, the tandem will get you there faster.

"Isn't that kinda cheating?" That's the first we heard that and we laughed a lot. Coming into a rest stop shortly thereafter someone yelled "Now there's double trouble".

I also tell people that my tandem has 2 horse power.

"Whoa, I'm seeing double!"

Hehe the alternative to 2 horsepower is a 4 stroke engine

"She's following you awfully close."

"Do you want to get on and show her how?"

"I thought tandems are slow going up hills", to which I have not figured out an appropriate response...
... how about "they are"
is slow, and you're even slower...]

"Oh no, she musta fallen off !!!"
Got a stunned look, then a good laugh.

"Don't pass him"

"I'm working hard, he is not"

whatever route I take, she's "right behind me 100%".

"its your turn to Pull" always gets a response from the 1/2 bike followers

"For she's not Pedaling."

"Who? There's someone on the back?"
or "She has to, we're chained together."
or "She'd better be because I'm not."

"Your bike is missing a motor." as we overtake someone.

'I steer, she pedals!'

"yes, I am pedaling"

I do want to get my wife a jersey that says "Back Seat Driver".

"Bike Pool. One less bike on the road."

"It's not her/my turn."

My wife generally responds that she's just for decoration.

he yelled "Better speed up, she's about to catch you!"