(Cover) - EN Showbiz - Mary-Kate Olsen is set to share her beau's newly purchased love nest.

The fashion designer and Olivier Sarkozy have apparently taken their relationship to the next level, despite only dating since May.

Olivier has reportedly spent over $6 million on a New York City townhouse which he plans to share with Mary-Kate, 26.

According to the New York Post, the 42-year-old half-brother of former French president Nicolas Sarkozy splashed out on the 4,200-square foot home because they both like "that it is old".

The property is 146 years old and is set across five floors. It boasts "nine fireplaces, a Juliet balcony in front and a large rear garden".

The townhouse is a twin property, and the sale has sparked speculation that Mary-Kate's sister Ashley will buy the neighbouring house.

A representative for Mary-Kate did not comment on the story.

Last month it was reported Olivier was planning to take his relationship with Mary-Kate to the next level.

"They are really, really happy," a source said. "And Olivier is buying a townhouse below 14th Street, to be with Mary-Kate. We are told they're not officially moving in together - they both think it's too early for that." (C) Cover Media