DOPPELGANGER: JESSICA BIEL Is Sly Stallone's Wife?

Here's Justin Timberlake's fiancee Jessica Biel at the London premiere of her new film "Total Recall" on Thursday (left) -- and Sylvester Stallone's wife Jennifer Flavin at the Hollywood premiere of "The Expendables 2" on Wednesday (right). Only one is 44, but both are bangin'.