His prickly swipe comes just weeks after Amanda Holden insinuated much the same thing about the buxom Brit model.
Brook, 32, had a brief fling with Golden Globe nominee Morrison in 2010.
The pair was photographed in a romantic clinch in 2010 outside a London Mayfair restaurant during the World Cup.
But Morrison’s comments reveal there is no love lost.
Morrison. 33, told the Mirror: “I once went out with a Brit. I didn’t realise she was such tabloid fodder.”
He elaborated by saying: “It was Kelly Brook … she’s not exactly the brightest bulb. We only went on one date.
Brook, a former Playboy model, is pregnant to rugby player boyfriend Thom Evans, 26.
Despite the slander Brook has been philosophical over Twitter.
She tweeted: “I’ve had one motto I’ve always lived by – Dignity always Dignity (unless your [sic] making someone laugh) xxxx”