HOLLYWOOD, Calif. — Mary-Kate Olsen is back on the singles market.

The 23-year-old star is no longer dating longtime boyfriend Nate Lowman. Her rep confirmed the breakup Wednesday to Us Weekly, revealing that the split happened some time ago.

Olsen and Lowman, a 30-year-old artist, started dating in 2008 after meeting through mutual friends.

But don't worry too much about the former Full House star's heart being broken. She was reportedly making out with actor Josh Hartnett over the weekend at a post-BAFTA party in London.

"They were making out in a dark corridor of the party," a source told People magazine.

Olsen is currently attending shows at London Fashion Week.