'Girls' Star: My Grandparents Saw Solo Sex Scene!

Allison Williams admits that she's had some "vulnerable" moments as the put-together Marnie Michaels on Girls, but one sex scene on the show really got to her -- and her grandparents saw it!

Williams comments on her solo bathroom sex scene in season one, telling Company magazine, "It’s the most private thing anyone can do, but being an actress can make you feel vulnerable. But of course, my grandparents watch the show."

While some actresses would be mortified, the actress wasn't too fazed by her elders seeing that scene. "I don’t know why I was so concerned though, they have been alive for virtually 90 years, so who am I to presume that sex never existed before me?"

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Girls seems to be a family affair for the Williams brood, with show creator and Golden Globe winner Lena Dunham telling David Letterman last week that Allison's news anchor father Brian Williams is "on set more than some of our [production assistants]."

"He's surprisingly jaunty about the whole thing," Dunham said of Alison's dad dealing with the ladies' sex scenes. "He comes and sits in Video Village and acts very proud of us. ... It's not a reality I ever thought I'd be existing in."

Season two of Girls is currently airing Sunday nights on HBO.