Kate Hudson, Oliver Hudson 'Dead' to their Biological Father

Former "Rules of Engagement" actor Oliver Hudson took aim at the father he shares with sister Kate Hudson over Father's Day, and apparently the barb hit home.

Oliver hopped on Instagram over Father's Day with a photo of himself as a youngster, a cherubic-faced Kate, and their biological father, musician Bill Hudson.

"Happy abandonment day," he pointedly captioned it.

That was apparently the last straw for Papa Bill, who has been lashing out at Oliver and Kate in new interviews.

"I say to them now, 'I set you free.' I had five birth children but I now consider myself a father of three. I no longer recognize Oliver and Kate as my own."

Bill even thinks it's time for the two to truly separate, and to quit capitalizing on the Hudson last name. Because obviously, when you hear Hudson, your first thought is Bill, right?

"I would ask them to stop using the Hudson name. They are no longer a part of my life. Oliver’s Instagram post was a malicious, vicious, premeditated attack. He is dead to me now. As is Kate. I am mourning their loss even though they are still walking this earth."

"I believe the drip, drip, drip of poison which started when they were kids finally took hold," he adds, referencing ex Goldie Hawn, who he married in 1976 and divorced in 1980.

"Goldie wanted to create this myth of a perfect family with Kurt [Russell] and she wanted me out. ... She gave interviews about her 'wonderful' relationship with Kurt and how the kids called him 'Pa.' She described me as an absent father. I’d call her and go, 'Goldie, how can you say that?' but she’d just reply: 'It’s a better story.'"

"I don't want to see either of my eldest children ever again," Bill concludes. "It's over."

That's probably okay with the two. Oliver has made his feelings clear, and Kate, in the past, had gone so far as to say her biological father didn't know her from "a hole in the wall."

"But I don't care. I have a dad. The bottom line is, you call your kids on their f**king birthday. I'm glad I had a dad who was there on my birthday."