KELLY OSBOURNE constantly cringed as she was growing up – because her rock star dad OZZY embarrassed her in front of friends.

The reality TV star is the envy of pals who insist it must be “cool” to have the Black Sabbath singer as her father.

But Kelly insists Ozzy frequently shamed her with his crazy pranks when she was a child.

In her autobiography, Fierce, she writes, “One time, Dad dressed as a werewolf and locked my friends in the garden shed. The kids were crying and Mum had to call their parents to collect them. Later, me and Jack went to check on him. He’d passed out and our ex-nanny was crawling on the carpet saying, ‘Ozzy, I know you’ve always wanted me.’ Dad was oblivious. She passed out too, so me, Jack and Mum smeared dog food, flour, and baked beans on her. We were p***ing ourselves laughing.

“One time, Mum bought me thongs instead of big knickers. As I bent down, Dad bellowed: ‘You’re wearing a thong, Kelly? Thongs are for whores!’ I jumped out of my skin.

“He pinned me down and cut off my thong in front of my school friends. They were standing there, mouths wide open as this piece of material no bigger than a string of dental floss was yanked out of my jeans. I died of embarrassment and burst into tears. Mum was hunched over the sink laughing her head off, screeching: ‘Ozzy! No!'”

The rocker was also banned from attending Kelly’s school parent evenings – because he’d always fall asleep speaking to her teachers.