kstewart060312_02_X17crop23.jpgKristen Stewart's mom and dad are divorcing after 27 years of marriage.

In the divorce petition filed on August 17 in LA Superior Court, Jules Stewart claims she and husband John have been estranged since June 15, 2010.

Jules, who works as a writer and director, cites irreconcilable differences as the reason for the split.

KStew's dad is a TV producer and stage manager.

The Twilight star, herself, has remained low key since news broke of her affair with married Snow White and the Huntsman director Rupert Sanders.