Austin Nichols and Sophia Bush

One Tree Hill is coming to an end, and so is another romance from the set.

Sophia Bush and her on-again-off-again boyfriend and co-star Austin Nichols are finished, Us Weekly reports.

One Tree Hill's last stand

A source tells the magazine that Bush gave Nichols the boot because she "didn't think he was the one." The real-life couple played husband and wife, Julian and Brooke Baker, on One Tree Hill.

Bush, 29, has a history of romancing her co-stars. She was first married to former series star Chad Michael Murray before they divorced in December 2006. A couple years later, she began dating James Lafferty. Finally, in May 2010, Bush confirmed that she and Nichols have been an item for at least four years.

The actress will have be able to widen her dating pool now that the series is coming to an end after nine seasons. The final episode will air on April 4 on The CW.