Singer ASHLEE SIMPSON has reportedly called time on her romance with VINCENT PIAZZA.

The pop star split from the Boardwalk Empire actor over the Thanksgiving holiday (22Nov12), according to New York Post gossip column Page Six.

A source tells the publication, "Vincent has been working a lot, so he hasn't been able to spend as much time with Ashlee, which has caused some problems. It was a mutual agreement to split, but things have been bumpy for a little while, so perhaps they might reconcile."

Simpson began dating Piazza in June 2011 after ending her marriage to rocker Pete Wentz, the father of her son Bronx Mowgli.