The news of Mary-Kate Olsen's engagement to Olivier Sarkozy [1] was a bit of a surprise at the end of last week, and now we have some confirmation in the form of a sparkly ring on her left hand [2]! Mary-Kate stepped out with her twin sister, Ashley Olsen [3], this afternoon in NYC, and while the girls were protecting themselves from the chilly Winter air, MK did manage to flash her new bling. At 27, Mary-Kate has been dating the 44-year-old Olivier for almost two years. The two are often seen cozying up courtside [4] at NBA games, and she's also become close with his two children from a previous relationship. Congrats to Mary-Kate and Olivier — read on to get a better look at the ring!