Pied-à-tierre: Mary-Kate Olsen, one half of the CFDA-winning line The Row, is about to participate in a serious game of shacking up. She has been dating 42-year-old Olivier Sarkozy (brother of Nicolas), who has just purchased a $6.25 million townhouse in the East Village, designed by famed architect James Renwick Jr. Sources tell The Post that they're planning to share the apartment. [Page Six]

Faux Follies: US Customs and Border Protection bureau in Los Angeles seized nearly 20,500 pairs of fake Louboutin heels being shipped over from China.  While their total retail value was priced around $18 Million, that’s nothing compared to the shelf value of Louboutin’s genuine fare. The imposters are likely to be destroyed. [The Daily Beast]

Branching Out: Prepsters rejoice!  Thom Browne, known for his tricolor stripes and short-suits, will soon launch a diffusion collection called Thom Grey.  “Thom Grey was created to exemplify a more youthful and university inspired sensibility,” the designer told WWD. The line will retail from $240 upwards of $1700 at Barneys New York, and will debut later this month. “Creatively, I’m never at a loss for ideas for shows and collections,” Browne told Newsweek/ The Daily Beast's Robin Givhan in July. “It’s been a good challenge to find a way to create a business to back it up.” [WWD]