Simon Cowell is worried his son will get bullied at school.

Simon Cowell

Simon Cowell

The 'X Factor' boss is terrified five-year-old Eric, whom he has with his girlfriend Lauren Silverman, will fall victim to cruel taunts as he grows up and he's adamant he'll storm straight down to the head teacher if he hears of anyone picking on his child.

Speaking to 'Extra', he said: "Just the thought of it [him being bullied]. If it ever happened to Eric, I would be right down at that school."

On the days when Eric isn't at school and Simon isn't busy working, they enjoy going out for a bike ride together because they relish in doing "normal things."

The 59-year-old music mogul explained: "Now we can cycle together. I love that. We just do normal things and I hope that stays."

Simon finds cycling easier now that he's lost "about 20lbs" by following a vegan diet.

The 'Britain's Got Talent' judge has admitted he "feels much better" since shedding the weight but really misses sinking his teeth into cheesy pizza.

He said when asked what he misses: "Pizza -- that's been really, really hard."

Simon decided to go vegan last month after his doctor directed him to an expert and he recommended omitting the animal products, as well as wheat, from his diet.

He said at the time: "A friend of mine, who is a doctor, recommended speaking to an expert, and I did it on a whim. I was allergic to melon, so I didn't eat it for six months, but I saw this man and he explained it and it made sense.

"Within 24 hours I changed my diet and I've not looked back since. You feel better, you look better. I cut out a lot of the stuff I shouldn't have been eating and that was primarily meat, dairy, wheat, sugar - those were the four main things."