Kim Kardashian is firing back against Fox News commentator Bill O'Reilly's criticism of her Elle photo shoot withJustin Bieber. "I thought the shoot was all in good fun - we had a good time," Kim said on Lopez Tonight of The Graduate-themed pictorial, which features the 29-year-old starlet in romantic scenarios with the 16-year-old "Baby" singer and appears in the magazine's September issue. "Everyone is entitled to their own opinion of it." In fact, the curvyKeeping Up With the Kardashians star gave Bill (who joked that Kim was "42" and noted, "I will tell you this: If a 16-year-old girl was pictured with a 29-year-old man in any of that, he'd be in big trouble") more grist for the mill when she told host George Lopez that she'd date Justin if "he was of legal age." Gushed Kim, "He definitely has this swag to him!"