Jack held her hand up to show the stranger their matching bracelets were displayed a synchronous cycle of lights. "Sorry, pal, she's taken."
Rose watched him shrug and walk away. "What was that about?"
"This is a matrimonial band."
"We're married?"
Jack grinned broadly. "Not exactly. They have a triune marriage based on people whose compatibility is indicated by these bracelets."
"They're fakes?"
Jack nodded at the Doctor, who waved back allowing Rose to see his own bracelet pulsed to match their own.
"Oh."

