It seemed like just a casual outing until we caught a glimpse of Mary-Kate's ring finger. Since the designer's wedding to Olivier Sarkozy last Fall, we hadn't yet seen both rings on that same finger, at the same time. Now, in a casual run around NYC, the newlywed is giving a surprise look at both pieces in all their glory.

She completed her vintage Cartier engagement ring [1] with just a simple solid gold band. Together, the rings don't compete, they complement. And, while each piece of jewelry could easily stand on its own, we have to admit, we like them better together. Read on for a closer look.