(Cover) - EN Showbiz - Heidi Klum insists the number one rule for her children is to "always look cool" before leaving the house.

The stunning supermodel has four kids; Leni, eight, Henry six, Johan, five-and-a-half and two-and-a-half-year-old Lou.

Heidi has joked that her family treat looking trendy as a serious business.

"We have a rule in the house," she said recently, according to People. "Rule No. 1 is always to look cool, and rule No. 2 is don't forget about rule No. 1. We have other rules... but the No. 1 rule is to always look cool."

Heidi added that her two eldest take the rule "very seriously". The 39-year-old star says son Henry likes to experiment with his look throughout the day.

"Henry changes clothes ten times a day and he wants to be very cool. I mean, he would wear a T-shirt and then he will wear a tie just around his neck, knotted, and then a belt over the shirt," she explained.

"He [has] very unusual ways of dressing where I'm like, 'Really? You want to put the belt over your T-shirt and the tie around your neck?' And he's like, 'Yes, mom. I'm cool.'" (C) Cover Media