Alan Thicke’s eldest sons, musician Robin Thicke and Brennan Thicke, have taken legal action against their father’s widow to enforce their prenup.

The brothers say they have been left with no choice but to go to the court in order to “honor the memory of their father, protect his legacy, and prevent his testamentary intentions from being undermined by avarice and overreaching of his third wife, Tanya Callau.” They have filed a petition in the Superior Court of Los Angeles on Tuesday to uphold the prenuptial agreement that their father, Robin Thicke and his third wife, Tanya Callau, signed before their marriage in 2005.

According to court documents, the brothers chose the legal route when Callau “threatened to make her claims fodder for ‘tabloid publicity’ unless the Co-Trustees agreed to participate in a mediation and succumb to her demands” to revise the prenup.

Brennan and Robin Thicke are co-trustess of Alan Thicke’s living trust.

In the trust, Alan left his three children equal shares in sixty percent of his estate, not including seventy-five percent of personal effects, and full control and ownership of a Carpinteria ranch.

While in the prenup, his third wife Tanya Callau was meant to get twenty-five percent of all personal effects, plus a $500,000 insurance policy and all death benefits from union memberships and pensions. She was also going to get forty percent of the remaining estate, and granted permission to go in living in the Carpinteria ranch provided that she pay for its upkeep and maintenance, and consult with Alan’s living sons on any major changes to the property.

In the court petition, Alex Weingarten Attorney to Brennan and Robin Thicke wrote that “Tanya asserts that there is no chance the ‘Prenup’ could withstand legal challenge and that she has very significant community rights in the Trust’s assets and rights of reimbursement with respect to improvements to the Ranch. Tanya also claims ‘Marvin rights’ asserting that she had to forgo opportunities to pursue and advance her own career in order to support Alan and be his companion and partner, including raising Carter.”

Carter Thicke is the son of Alan Thicke with his second wife Gina Tolleson.

“My clients made every effort to resolve this without the need for going to court,”  Weingarten, said in a statement on Tuesday.

Callau’s Attorney, Adam Streisand, though has countered with a statement. “Tanya Thicke has never threatened to take private family matters public and she never has,” he wrote. “It is clear that Alan’s sons have chosen this distasteful public smear tactic to bully Tanya, by stirring up the tabloid media, filing a bogus lawsuit, and refusing family mediation. Tanya is still grieving the death of her beloved husband and out of respect for Alan’s memory intends to handle his son’s false statements privately.”

The Thicke brothers are seeking the court’s instruction on whether the trust’s property is considered Alan’s separate property since Callau’s challenge to the prenup meant that she waived her community rights to the late actor’s properties by signing it.

Alan Thicke passed away on December 13, 2016 in Burbank following a collapse  while playing ice hockey with youngest son, Carter. He was rushed to the Providence Saint Joseph Medical center in Burbank. He died of an Aortic dissection, and was 69 years old.