Rumours have circulated in recent months but this time it's official, Mary-Kate Olsen is engaged to marry boyfriend, Olivier Sarkozy.  According to US Weekly the 27-year-old actress turned designer and the 44-year-old banker plan to tie the knot. Mary-Kate and Oliver, who is the half-brother of former French president Nicholas Sarkozy, first went public with their romance back in 2012 and live together in a $6.25 million townhouse in New York. The site announced the couple's engagement after it was exclusively confirmed by a source.  The Olsen family are said to approve of the pairing. "Mary-Kate's family thinks Olivier is the best thing to happen to her... they love him." Sarkozy who was previously wed to Charlotte Bernard, with whom he has two kids, Julien and Margo, is said to have become a better father thanks to his wife-to-be. A source previously told US Weekly, "Mary-Kate has made him a better father. She remembers all the kids' special events." Adding: "She thinks he's a great dad."