Michael Buckner, Getty Images

Bret Michaels has called off his engagement to his longtime girlfriend Kristi Gibson.

Gibson is the mother of the Poison frontman's two young daughters, Raine and Jorja Michaels and she was also by the singer's side throughout a series of medical emergencies in 2010.

Michaels, 49, asked Gibson to marry him in an episode of his VH1 reality show Bret Michaels: Life As I Know It, which aired in Dec. 2010.

A spokesman for Michaels says, "Although the couple have separated, they remain great friends and are committed to jointly raising their two daughters, Raine and Jorja."

In 2007, Michaels starred in the dating competition series Rock of Love with Bret Michaels. The show ran for three seasons on VH1.