Sarah Silverman's Mom Saw Her Sex Spanking Bruise (VIDEO)

Sarah Silverman is getting spanked by her new boyfriend, 'Family Guy' writer/producer Alec Sulkin, and her mom knows because she saw the hand-shaped bruises.

"You know what's great about parents," Sarah told David Letterman Wednesday night, "is that when you get famous you can do anything you want and they can't do anything about it."

On a recent trip home, Sarah said that she and her mom were hanging out in the bathroom while she waited for the shower to heat up. As she went to get into the shower, her mom said in horror, "Sarah, what is that?!"

"I looked in the mirror behind me and noticed that on my tushie is a bruise the exact same shape of a hand," she said. "And I was able to just say, I'm sleeping with a man that spanks me."