Double-decker Bus

A blonde, a redhead and a brunette sign up with a tourist group for a chartered-double-decker bus trip to London. There are only 2 seats left on the bottom of the bus, and only 1 seat on the top of the bus available when they board. The young ladies decide to take turns riding on the top, and flip a coin to see who gets the first turn. The blonde wins the toss.

A couple of hours later, it's the redhead's turn. She takes the steps to the top and sees the blonde, sitting there scared half
to death. She's clutching the seat in front of her so hard that her knuckles are white.

"What's goin' on?" the redhead asks. "We're havin' a grand old time down below, singing and laughing."

The blonde replies, "Yeah, but you've got a driver."