Sean StewartGuess his dadJust who is this hunk splashing about in the Malibu surf?

Well, he's not a celebrity as such... but his dad and sister are.

Step forward Rod Stewart's son, Sean, brother of lanky model and Hollywood It Girl Kimberly.

The 25-year-old is one of Rod's seven kids and comes from his marriage to Alana Stewart, along with Kimberly.

And young Sean is clearly proud of his heritage, as he's got Stewart tattooed across his belly. Bless.

But back in 2005 - around the time Rod's youngest child Alistair was born (to Penny Lancaster) - Sean was quoted as saying:

"I love my dad, but a lot of celebrity children grow up f****d up because our parents are out of town a lot and it makes us feel unwanted.

G Rod Stewart and Kimberly Stewart apr 2004Rod Stewart with daughter Kimberly"All celebrity children are messed-up."

At 16, he was expelled from Beverly Hills High School and had to attend Alcoholics Anonymous meetings after developing a drinking problem.

And in 2002 he served a three-month jail sentence in California after being found guilty of assault.

However, he's now followed his sister onto the catwalk... despite his many body scribblings.