Joe Jonas caused quite a stir in Milan during the men’s fashion shows. Girls camped outside the Calvin Klein show hoping for a glimpse of the singer, who attended Sunday’s presentation and party. They also flocked to his hotel, the Principe Di Savoia, which left Jonas so mystified, he took a photo of the crowd and posted it on Twitter. Jonas also attended the Details magazine bash Saturday night along with stylist Brad Goreski and Calvin Klein designer Italo Zucchelli. At one point, Jonas was grabbed by a handsome male model who mistook him for an agent, “but his security just laughed it off,” a spy told us.